Background Low O 2  tension dilates coronary arteries and high O 2  tension is a coronary vasoconstrictor but reports on O 2 -dependent effects on ventricular performance diverge. Yet oxygen supplementation remains first line treatment in cardiovascular disease. We hypothesized that hypoxia improves and hyperoxia worsens myocardial performance.
Background
Low O 2  tension dilates coronary arteries and high O 2  tension is a coronary vasoconstrictor but reports on O 2 -dependent effects on ventricular performance diverge. Yet oxygen supplementation remains first line treatment in cardiovascular disease. We hypothesized that hypoxia improves and hyperoxia worsens myocardial performance.Methods Seven male volunteers (mean age 38 ± 3 years) were examined with echocardiography at respiratory equilibrium during: 1) normoxia (≈21% O 2 , 79% N 2 ), 2) while inhaling a hypoxic gas mixture (≈11% O 2 , 89% N 2 ), and 3) while inhaling 100% O 2 . Tissue Doppler recordings were acquired in the apical 4-chamber, 2-chamber, and long-axis views. Strain rate and tissue tracking displacement analyses were carried out in each segment of the 16-segment left ventricular model and in the basal, middle and apical portions of the right ventricle.
Methods
Seven male volunteers (mean age 38 ± 3 years) were examined with echocardiography at respiratory equilibrium during: 1) normoxia (≈21% O 2 , 79% N 2 ), 2) while inhaling a hypoxic gas mixture (≈11% O 2 , 89% N 2 ), and 3) while inhaling 100% O 2 . Tissue Doppler recordings were acquired in the apical 4-chamber, 2-chamber, and long-axis views. Strain rate and tissue tracking displacement analyses were carried out in each segment of the 16-segment left ventricular model and in the basal, middle and apical portions of the right ventricle.Results Heart rate increased with hypoxia (68 ± 4 bpm at normoxia vs. 79 ± 5 bpm, P < 0.001) and decreased with hyperoxia (59 ± 5 bpm, P < 0.001 vs. normoxia). Hypoxia increased strain rate in four left ventricular segments and global systolic contraction amplitude was increased (normoxia: 9.76 ± 0.41 vs hypoxia: 10.87 ± 0.42, P < 0.001). Tissue tracking displacement was reduced in the right ventricular segments and tricuspid regurgitation increased with hypoxia (7.5 ± 1.9 mmHg vs. 33.5 ± 1.8 mmHg, P < 0.001). The TEI index and E/E' did not change with hypoxia. Hyperoxia reduced strain rate in 10 left ventricular segments, global systolic contraction amplitude was decreased (8.83 ± 0.38, P < 0.001 vs. normoxia) while right ventricular function was unchanged. The spectral and tissue Doppler TEI indexes were significantly increased but E/E' did not change with hyperoxia.
Results
Heart rate increased with hypoxia (68 ± 4 bpm at normoxia vs. 79 ± 5 bpm, P < 0.001) and decreased with hyperoxia (59 ± 5 bpm, P < 0.001 vs. normoxia). Hypoxia increased strain rate in four left ventricular segments and global systolic contraction amplitude was increased (normoxia: 9.76 ± 0.41 vs hypoxia: 10.87 ± 0.42, P < 0.001). Tissue tracking displacement was reduced in the right ventricular segments and tricuspid regurgitation increased with hypoxia (7.5 ± 1.9 mmHg vs. 33.5 ± 1.8 mmHg, P < 0.001). The TEI index and E/E' did not change with hypoxia. Hyperoxia reduced strain rate in 10 left ventricular segments, global systolic contraction amplitude was decreased (8.83 ± 0.38, P < 0.001 vs. normoxia) while right ventricular function was unchanged. The spectral and tissue Doppler TEI indexes were significantly increased but E/E' did not change with hyperoxia.Conclusion Hypoxia improves and hyperoxia worsens systolic myocardial performance in healthy male volunteers. Tissue Doppler measures of diastolic function are unaffected by hypoxia/hyperoxia which support that the changes in myocardial performance are secondary to changes in vascular tone. It remains to be settled whether oxygen therapy to patients with heart disease is a consistent rational treatment.
Conclusion
Hypoxia improves and hyperoxia worsens systolic myocardial performance in healthy male volunteers. Tissue Doppler measures of diastolic function are unaffected by hypoxia/hyperoxia which support that the changes in myocardial performance are secondary to changes in vascular tone. It remains to be settled whether oxygen therapy to patients with heart disease is a consistent rational treatment.

Introduction Low oxygen tension dilates coronary arteries and high oxygen tension is a coronary vasoconstrictor. Yet oxygen supplementation remains first line treatment in cardiovascular disease states such as myocardial infarction and pulmonary oedema. Endothelium-dependent vasodilation is reduced in patients with ischemic heart disease [ 1 ] and such patients are believed to have a reduced ability to counteract the circulatory consequences of systemic (air line travel, high altitude stay) and regional (coronary artery stenosis) hypoxia. Spontaneous nocturnal hypoxia with desaturation for hours is a frequent phenomenon in patients with severe coronary artery disease [ 2 ]. Left atrial, left ventricular (LV), and right ventricular (RV) end-systolic diameter fall during simulated extreme altitude [ 3 ] and during moderate altitude exposure [ 4 ]. There is controversy concerning myocardial performance during hypoxia; improvement [ 4 ], no change [ 3 , 5 , 6 ]. and worsening [ 7 ] of left ventricular systolic function, have been described. One study looked at diastolic function expressed as E/A ratio and found a reduction with hypoxia [ 3 ]. Hyperoxia, a condition in which the total oxygen content of the body is increased above that normally existing at sea level, is associated with impairment of cardiac relaxation and increased left ventricular filling pressures in patients with and without congestive heart failure [ 8 ]. Tissue Doppler imaging (TDI) objectively derives measurements of contraction and relaxation velocities directly from the myocardium and thus yields information not previously accessible by echocardiography [ 9 ]. We used TDI to study myocardial performance in healthy volunteers and we hypothesized that hypoxia increases and hyperoxia reduces myocardial performance.
Introduction
Low oxygen tension dilates coronary arteries and high oxygen tension is a coronary vasoconstrictor. Yet oxygen supplementation remains first line treatment in cardiovascular disease states such as myocardial infarction and pulmonary oedema.Endothelium-dependent vasodilation is reduced in patients with ischemic heart disease [ 1 ] and such patients are believed to have a reduced ability to counteract the circulatory consequences of systemic (air line travel, high altitude stay) and regional (coronary artery stenosis) hypoxia. Spontaneous nocturnal hypoxia with desaturation for hours is a frequent phenomenon in patients with severe coronary artery disease [ 2 ]. Left atrial, left ventricular (LV), and right ventricular (RV) end-systolic diameter fall during simulated extreme altitude [ 3 ] and during moderate altitude exposure [ 4 ]. There is controversy concerning myocardial performance during hypoxia; improvement [ 4 ], no change [ 3 , 5 , 6 ]. and worsening [ 7 ] of left ventricular systolic function, have been described. One study looked at diastolic function expressed as E/A ratio and found a reduction with hypoxia [ 3 ].Hyperoxia, a condition in which the total oxygen content of the body is increased above that normally existing at sea level, is associated with impairment of cardiac relaxation and increased left ventricular filling pressures in patients with and without congestive heart failure [ 8 ].Tissue Doppler imaging (TDI) objectively derives measurements of contraction and relaxation velocities directly from the myocardium and thus yields information not previously accessible by echocardiography [ 9 ]. We used TDI to study myocardial performance in healthy volunteers and we hypothesized that hypoxia increases and hyperoxia reduces myocardial performance.Material and Methods Subjects Seven healthy men, (age 25–46 (mean 38) years) completed the study. All subjects were normotensive, non-smokers, on no medication, had a normal left ventricular function by 2-D echocardiography, and had no family history of ischemic heart disease. The local ethical committee approved the study. Ventilation system We used a system consisting of a ventilator, a gas analyser with pulse oximeter, and a computer. Computer programs control the experimental procedure and continuously collect data from the ventilator and gas analyser [ 10 ]. Echocardiography Echocardiography was performed from the apical acoustic window. Tissue Doppler recordings were acquired as digital loops in the apical 4-chamber, 2-chamber, and long-axis views [ 9 ]. To avoid aliasing, the settings of the ultrasound equipment and colour-coded area were adjusted to obtain the highest possible frame rate. We measured peak strain in the 16-segment left ventricular model and in 3 segments in the right. From the color-coded tissue tracking image, the motion amplitude toward the apex in systole was recorded in each segment. The global systolic contraction amplitude (GSCA) was calculated as the average shortening amplitude of all 16 segments. The peak E velocity was obtained by pulsed Doppler measurements of the mitral inflow at the tip of the mitral leaflets. We further assessed isovolumetric acceleration, TEI index (spectral and TDI), tricuspid regurgitation and pulmonary ejection time. The tissue E' velocity was obtained by Tissue Doppler at the lateral mitral annulus. E/E' has been proposed as a tool for assessing LV filling pressures that combines the influence of transmitral driving pressure and myocardial relaxation [ 11 ]. The TEI index (spectral or TDI), a combined measure of systolic and diastolic function, was assessed by Doppler time intervals from the mitral inflow and LV outflow tract or the time intervals were obtained by TDI at the lateral mitral annulus. The TEI index was calculated by a-b/b where the time interval "a" was measured from cessation to onset of mitral inflow and the time interval "b" was the duration of the LV outflow velocity profile. To minimize the variability of the measurements, all ECHO recordings were performed and analyzed in a blinded fashion by the same author (P.S.). Study protocol TDI was performed when the subjects had rested for 15 minutes breathing room air (SpO 2  97.9 ± 0.1 %), after 5 minutes of respiratory equilibrium during hypoxia (SpO 2  77.6 ± 1.2 %), and after 5 minutes of respiratory equilibrium during hyperoxia (SpO 2  99.0 ± 0.2 %). Heart rate was continuously recorded on computer by means of the pulse oximeter. Blood pressure was measured once during each of the three respiratory steady state situations by an automatic blood pressure measuring device based on the oscillometric method. Statistical analysis All data are presented as mean ± SEM. Comparisons of the responses to changes in F i O 2  (normoxia, hypoxia and hyperoxia) were made with a one-way repeated-measures analysis of variance. The Student-Newman-Keuls test was used post hoc to identify pairwise differences. Differences were considered statistically significant when P < 0.05.
Material and Methods
Subjects Seven healthy men, (age 25–46 (mean 38) years) completed the study. All subjects were normotensive, non-smokers, on no medication, had a normal left ventricular function by 2-D echocardiography, and had no family history of ischemic heart disease. The local ethical committee approved the study.
Subjects
Seven healthy men, (age 25–46 (mean 38) years) completed the study. All subjects were normotensive, non-smokers, on no medication, had a normal left ventricular function by 2-D echocardiography, and had no family history of ischemic heart disease. The local ethical committee approved the study.Ventilation system We used a system consisting of a ventilator, a gas analyser with pulse oximeter, and a computer. Computer programs control the experimental procedure and continuously collect data from the ventilator and gas analyser [ 10 ].
Ventilation system
We used a system consisting of a ventilator, a gas analyser with pulse oximeter, and a computer. Computer programs control the experimental procedure and continuously collect data from the ventilator and gas analyser [ 10 ].Echocardiography Echocardiography was performed from the apical acoustic window. Tissue Doppler recordings were acquired as digital loops in the apical 4-chamber, 2-chamber, and long-axis views [ 9 ]. To avoid aliasing, the settings of the ultrasound equipment and colour-coded area were adjusted to obtain the highest possible frame rate. We measured peak strain in the 16-segment left ventricular model and in 3 segments in the right. From the color-coded tissue tracking image, the motion amplitude toward the apex in systole was recorded in each segment. The global systolic contraction amplitude (GSCA) was calculated as the average shortening amplitude of all 16 segments. The peak E velocity was obtained by pulsed Doppler measurements of the mitral inflow at the tip of the mitral leaflets. We further assessed isovolumetric acceleration, TEI index (spectral and TDI), tricuspid regurgitation and pulmonary ejection time. The tissue E' velocity was obtained by Tissue Doppler at the lateral mitral annulus. E/E' has been proposed as a tool for assessing LV filling pressures that combines the influence of transmitral driving pressure and myocardial relaxation [ 11 ]. The TEI index (spectral or TDI), a combined measure of systolic and diastolic function, was assessed by Doppler time intervals from the mitral inflow and LV outflow tract or the time intervals were obtained by TDI at the lateral mitral annulus. The TEI index was calculated by a-b/b where the time interval "a" was measured from cessation to onset of mitral inflow and the time interval "b" was the duration of the LV outflow velocity profile. To minimize the variability of the measurements, all ECHO recordings were performed and analyzed in a blinded fashion by the same author (P.S.).
Echocardiography
Echocardiography was performed from the apical acoustic window. Tissue Doppler recordings were acquired as digital loops in the apical 4-chamber, 2-chamber, and long-axis views [ 9 ]. To avoid aliasing, the settings of the ultrasound equipment and colour-coded area were adjusted to obtain the highest possible frame rate. We measured peak strain in the 16-segment left ventricular model and in 3 segments in the right. From the color-coded tissue tracking image, the motion amplitude toward the apex in systole was recorded in each segment. The global systolic contraction amplitude (GSCA) was calculated as the average shortening amplitude of all 16 segments. The peak E velocity was obtained by pulsed Doppler measurements of the mitral inflow at the tip of the mitral leaflets. We further assessed isovolumetric acceleration, TEI index (spectral and TDI), tricuspid regurgitation and pulmonary ejection time. The tissue E' velocity was obtained by Tissue Doppler at the lateral mitral annulus. E/E' has been proposed as a tool for assessing LV filling pressures that combines the influence of transmitral driving pressure and myocardial relaxation [ 11 ]. The TEI index (spectral or TDI), a combined measure of systolic and diastolic function, was assessed by Doppler time intervals from the mitral inflow and LV outflow tract or the time intervals were obtained by TDI at the lateral mitral annulus. The TEI index was calculated by a-b/b where the time interval "a" was measured from cessation to onset of mitral inflow and the time interval "b" was the duration of the LV outflow velocity profile. To minimize the variability of the measurements, all ECHO recordings were performed and analyzed in a blinded fashion by the same author (P.S.).Study protocol TDI was performed when the subjects had rested for 15 minutes breathing room air (SpO 2  97.9 ± 0.1 %), after 5 minutes of respiratory equilibrium during hypoxia (SpO 2  77.6 ± 1.2 %), and after 5 minutes of respiratory equilibrium during hyperoxia (SpO 2  99.0 ± 0.2 %). Heart rate was continuously recorded on computer by means of the pulse oximeter. Blood pressure was measured once during each of the three respiratory steady state situations by an automatic blood pressure measuring device based on the oscillometric method.
Study protocol
TDI was performed when the subjects had rested for 15 minutes breathing room air (SpO 2  97.9 ± 0.1 %), after 5 minutes of respiratory equilibrium during hypoxia (SpO 2  77.6 ± 1.2 %), and after 5 minutes of respiratory equilibrium during hyperoxia (SpO 2  99.0 ± 0.2 %). Heart rate was continuously recorded on computer by means of the pulse oximeter. Blood pressure was measured once during each of the three respiratory steady state situations by an automatic blood pressure measuring device based on the oscillometric method.Statistical analysis All data are presented as mean ± SEM. Comparisons of the responses to changes in F i O 2  (normoxia, hypoxia and hyperoxia) were made with a one-way repeated-measures analysis of variance. The Student-Newman-Keuls test was used post hoc to identify pairwise differences. Differences were considered statistically significant when P < 0.05.
Statistical analysis
All data are presented as mean ± SEM. Comparisons of the responses to changes in F i O 2  (normoxia, hypoxia and hyperoxia) were made with a one-way repeated-measures analysis of variance. The Student-Newman-Keuls test was used post hoc to identify pairwise differences. Differences were considered statistically significant when P < 0.05.Results Respiratory parameters and hemodynamics FiO 2  and FeO 2  decreased with hypoxia and increased with 100% oxygen breathing (table 1). FeCO 2  and tidal volume were unchanged in all three test situations, reflecting that the subjects were in respiratory steady state. There was a small, but statistically significant  decrease  in respiratory rate from normoxia to hypoxia, which might reflect that the subjects were more accustomed to the test situation at this stage. There was a significant increase in heart rate with hypoxia and a decrease with hyperoxia (figure  1 ). Neither systolic (126 ± 6, 123 ± 8, 122 ± 12 mmHg, respectively, P = ns) nor diastolic blood pressure (80 ± 5, 78 ± 8, 81 ± 6 mmHg, respectively, P = ns) changed significantly with test situation. Figure 1 Bar graph depicting heart rate during normoxia, hypoxia and hyperoxia. ** P < 0.01 vs. normoxia. TDI and spectral echocardiography, hypoxia A significant increase in strain rate was found in 4 segments (figure  2 ). GSCA increased with hypoxia (9.76 ± 0.41 vs. 10.87 ± 0.42, P < 0.001, figure  3 ). Tissue tracking displacement was reduced in all three right ventricular segments (figure  4 ) and systolic tricuspid regurgitation increased with hypoxia (figure  5 ). The TEI index (spectral or TDI) and E/E' did not change with hypoxia. Figure 2 Comparison of peak systolic strain in the 16-segment left ventricular model illustrating the effects of hypoxia and hyperoxia.  A , Anterior;  B , basal;  D , distal;  I , inferior;  L , lateral;  M , mid;  P , posterior;  S , septal. * P < 0.05, ** P < 0.01 vs. normoxia. Figure 3 Tissue tracking score index on the basis of the 16-segment left ventricular model illustrating the effects of hypoxia and hyperoxia. Figure 4 Comparison of peak systolic strain in the right ventricle model illustrating the effects of hypoxia and hyperoxia. * P < 0.05. Figure 5 Bar graph depicting systolic tricuspid regurgitation during normoxia, hypoxia and hyperoxia. ** P < 0.01 vs. normoxia. TDI and spectral echocardiography, hyperoxia Hyperoxia worsened left ventricular function. Strain rate was reduced in 10 segments (figure  2 ) with preponderance in the lateral and anterior segments. GSCA was reduced (8.83 ± 0.38, P < 0.001 vs. normoxia). Tissue tracking displacement did not change in the right ventricular segments (figure  4 ) and systolic tricuspid regurgitation was unchanged compared with normoxia (figure  5 )). The TDI TEI index was significantly increased with hyperoxia (0.32 ± 0.04 vs. 0.45 ± 0.05, P < 0.001) and the spectral TEI index showed similar changes. E/E' did not change with hyperoxia.
Results
Respiratory parameters and hemodynamics FiO 2  and FeO 2  decreased with hypoxia and increased with 100% oxygen breathing (table 1). FeCO 2  and tidal volume were unchanged in all three test situations, reflecting that the subjects were in respiratory steady state. There was a small, but statistically significant  decrease  in respiratory rate from normoxia to hypoxia, which might reflect that the subjects were more accustomed to the test situation at this stage. There was a significant increase in heart rate with hypoxia and a decrease with hyperoxia (figure  1 ). Neither systolic (126 ± 6, 123 ± 8, 122 ± 12 mmHg, respectively, P = ns) nor diastolic blood pressure (80 ± 5, 78 ± 8, 81 ± 6 mmHg, respectively, P = ns) changed significantly with test situation. Figure 1 Bar graph depicting heart rate during normoxia, hypoxia and hyperoxia. ** P < 0.01 vs. normoxia.
Respiratory parameters and hemodynamics
FiO 2  and FeO 2  decreased with hypoxia and increased with 100% oxygen breathing (table 1). FeCO 2  and tidal volume were unchanged in all three test situations, reflecting that the subjects were in respiratory steady state. There was a small, but statistically significant  decrease  in respiratory rate from normoxia to hypoxia, which might reflect that the subjects were more accustomed to the test situation at this stage.decreaseThere was a significant increase in heart rate with hypoxia and a decrease with hyperoxia (figure  1 ). Neither systolic (126 ± 6, 123 ± 8, 122 ± 12 mmHg, respectively, P = ns) nor diastolic blood pressure (80 ± 5, 78 ± 8, 81 ± 6 mmHg, respectively, P = ns) changed significantly with test situation.TDI and spectral echocardiography, hypoxia A significant increase in strain rate was found in 4 segments (figure  2 ). GSCA increased with hypoxia (9.76 ± 0.41 vs. 10.87 ± 0.42, P < 0.001, figure  3 ). Tissue tracking displacement was reduced in all three right ventricular segments (figure  4 ) and systolic tricuspid regurgitation increased with hypoxia (figure  5 ). The TEI index (spectral or TDI) and E/E' did not change with hypoxia. Figure 2 Comparison of peak systolic strain in the 16-segment left ventricular model illustrating the effects of hypoxia and hyperoxia.  A , Anterior;  B , basal;  D , distal;  I , inferior;  L , lateral;  M , mid;  P , posterior;  S , septal. * P < 0.05, ** P < 0.01 vs. normoxia. Figure 3 Tissue tracking score index on the basis of the 16-segment left ventricular model illustrating the effects of hypoxia and hyperoxia. Figure 4 Comparison of peak systolic strain in the right ventricle model illustrating the effects of hypoxia and hyperoxia. * P < 0.05. Figure 5 Bar graph depicting systolic tricuspid regurgitation during normoxia, hypoxia and hyperoxia. ** P < 0.01 vs. normoxia.
TDI and spectral echocardiography, hypoxia
A significant increase in strain rate was found in 4 segments (figure  2 ). GSCA increased with hypoxia (9.76 ± 0.41 vs. 10.87 ± 0.42, P < 0.001, figure  3 ). Tissue tracking displacement was reduced in all three right ventricular segments (figure  4 ) and systolic tricuspid regurgitation increased with hypoxia (figure  5 ). The TEI index (spectral or TDI) and E/E' did not change with hypoxia.TDI and spectral echocardiography, hyperoxia Hyperoxia worsened left ventricular function. Strain rate was reduced in 10 segments (figure  2 ) with preponderance in the lateral and anterior segments. GSCA was reduced (8.83 ± 0.38, P < 0.001 vs. normoxia). Tissue tracking displacement did not change in the right ventricular segments (figure  4 ) and systolic tricuspid regurgitation was unchanged compared with normoxia (figure  5 )). The TDI TEI index was significantly increased with hyperoxia (0.32 ± 0.04 vs. 0.45 ± 0.05, P < 0.001) and the spectral TEI index showed similar changes. E/E' did not change with hyperoxia.
TDI and spectral echocardiography, hyperoxia
Hyperoxia worsened left ventricular function. Strain rate was reduced in 10 segments (figure  2 ) with preponderance in the lateral and anterior segments. GSCA was reduced (8.83 ± 0.38, P < 0.001 vs. normoxia). Tissue tracking displacement did not change in the right ventricular segments (figure  4 ) and systolic tricuspid regurgitation was unchanged compared with normoxia (figure  5 )). The TDI TEI index was significantly increased with hyperoxia (0.32 ± 0.04 vs. 0.45 ± 0.05, P < 0.001) and the spectral TEI index showed similar changes. E/E' did not change with hyperoxia.Discussion The main findings of the present study of healthy volunteers are: 1) hypoxia increased strain rate and tissue tracking displacement. 2) Hypoxia increased tricuspid regurgitation and reduced right ventricular tissue tracking displacement. 3) Hyperoxia reduced strain rate and tissue tracking displacement and increased the TEI index. The novelty of our findings, when compared to the literature, is the demonstration that longitudinal myocardial function, and thus the function of the subendocardium, is sensitive to moderate changes in inspired oxygen. Patients with ischemic heart disease and heart failure frequently encounter hypoxia but the consequences of hypoxia on left ventricular function remain a matter of controversy, in part because of differences in methodology and the measured parameters. In early studies using roentgenkymograms [ 12 ] and dye injection [ 13 ] hypoxia was shown to increase cardiac output at rest despite reduced [ 13 ] or unchanged [ 12 ] stroke volume. The authors explained the increase in cardiac output by increased heart rate [ 12 , 13 ] Myocardial blood flow in the left and right ventricles increased at high altitude in dogs studied with radioactive microspheres [ 14 ] and in healthy controls using positron emission tomography [ 15 ]. In a study using M-mode echocardiography at high altitude [ 4 ] percent fractional shortening and velocity of circumferential fiber shortening remained normal while LV isovolumetric contraction time shortened. Echocardiography was also employed in a simulated ascent of Mount Everest [ 3 ] and an insignificant increase in fractional shortening and ejection fraction was found. It is generally accepted that right-sided pressures increase with hypoxia [ 3 , 14 ] We speculate that the improvement in tissue tracking displacement in our study reflects the systemic vasodilation which is another consequence of hypoxia [ 16 ]. On the other hand, RV-systolic function decreased which is likely to be correlated to the increased systolic pulmonary pressure reflecting the increased pulmonary vascular resistance during hypoxia. Hemoglobin saturation in healthy persons increase very little from breathing room air to breathing 100% oxygen. Nevertheless, profound cardiovascular effects were found. This is probably because of an anticipated increase in oxygen dissolved into plasma from 0.32% to 2.09% [ 17 ]. Hyperoxia is a possible product of oxygen therapy when administered to patients with heart disease during acute illness. Hyperoxia reduces cardiac output as documented with roentgenkymograms [ 12 ], dye injection [ 18 , 19 ]., echocardiography [ 20 ] heart catheterisation [ 8 ] and indirectly by measurement of isometric systolic tension by means of strain gauge in dogs [ 21 ]. Reduced cardiac output with hyperoxia has even been demonstrated in patients with myocardial infarction using dye injection [ 22 ]. Some of the reduction in cardiac output may be explained by the observation that hyperoxia reduces heart rate as seen in our study and previously [ 19 , 23 - 25 ] Reduced heart rate is, however, not an entirely consistent finding [ 8 , 20 , 22 , 26 ] but in these four studies this could be because of high sympathetic tone (stay in a hyperbaric chamber [ 20 ], acute myocardial infarction [ 22 ], open heart surgery [ 26 ], heart catheterisation [ 8 ]). We found that heart rate increased with hypoxia and decreased with hyperoxia. This might have affected our measures of LV systolic and diastolic function but we consider this unlikely on the basis of our previous studies [ 11 , 27 ] demonstrating that TEI index, strain rate and the tissue tracking was unrelated to heart rate. During hypoxia as well as hyperoxia no change in LV filling pressure was noted as the E/E' ratio was unchanged. The individual parameters in the E/E' ratio are known to be influenced by heart rate but as a ratio it seems independent of heart rate and load conditions [ 11 , 27 ]. Therefore, we did not perform any adjustments for heart rate in the evaluation of LV diastolic function. Because of the finding of no change [ 19 ] or a discrete rise [ 18 , 22 ] in blood pressure, a reduction in cardiac output results in an increased systemic vascular resistance during hyperoxia [ 18 , 19 , 22 ] Regardless of the fact that sympathetic tone may be affected by hyperoxia, even after complete sympathetic blockade myocardial contractile force remains reduced [ 26 ]. In the present study both tissue tracking displacement and strain rate worsened during hyperoxia. It seems plausible that this deterioration could be explained by systemic vasoconstriction [ 21 ] increasing afterload. In conclusion, hypoxia improves and hyperoxia worsens systolic myocardial performance in healthy male volunteers. TDI measures of diastolic function are unaffected by hypoxia/hyperoxia which support that the changes in myocardial performance are secondary to changes in vascular tone. It remains to be settled whether oxygen therapy to patients with heart disease is a rational treatment that may sometimes be harmful or whether supplemental oxygen consistently results in an overall gain in delivered oxygen.
Discussion
The main findings of the present study of healthy volunteers are: 1) hypoxia increased strain rate and tissue tracking displacement. 2) Hypoxia increased tricuspid regurgitation and reduced right ventricular tissue tracking displacement. 3) Hyperoxia reduced strain rate and tissue tracking displacement and increased the TEI index. The novelty of our findings, when compared to the literature, is the demonstration that longitudinal myocardial function, and thus the function of the subendocardium, is sensitive to moderate changes in inspired oxygen.Patients with ischemic heart disease and heart failure frequently encounter hypoxia but the consequences of hypoxia on left ventricular function remain a matter of controversy, in part because of differences in methodology and the measured parameters. In early studies using roentgenkymograms [ 12 ] and dye injection [ 13 ] hypoxia was shown to increase cardiac output at rest despite reduced [ 13 ] or unchanged [ 12 ] stroke volume. The authors explained the increase in cardiac output by increased heart rate [ 12 , 13 ] Myocardial blood flow in the left and right ventricles increased at high altitude in dogs studied with radioactive microspheres [ 14 ] and in healthy controls using positron emission tomography [ 15 ]. In a study using M-mode echocardiography at high altitude [ 4 ] percent fractional shortening and velocity of circumferential fiber shortening remained normal while LV isovolumetric contraction time shortened. Echocardiography was also employed in a simulated ascent of Mount Everest [ 3 ] and an insignificant increase in fractional shortening and ejection fraction was found. It is generally accepted that right-sided pressures increase with hypoxia [ 3 , 14 ] We speculate that the improvement in tissue tracking displacement in our study reflects the systemic vasodilation which is another consequence of hypoxia [ 16 ]. On the other hand, RV-systolic function decreased which is likely to be correlated to the increased systolic pulmonary pressure reflecting the increased pulmonary vascular resistance during hypoxia.Hemoglobin saturation in healthy persons increase very little from breathing room air to breathing 100% oxygen. Nevertheless, profound cardiovascular effects were found. This is probably because of an anticipated increase in oxygen dissolved into plasma from 0.32% to 2.09% [ 17 ]. Hyperoxia is a possible product of oxygen therapy when administered to patients with heart disease during acute illness. Hyperoxia reduces cardiac output as documented with roentgenkymograms [ 12 ], dye injection [ 18 , 19 ]., echocardiography [ 20 ] heart catheterisation [ 8 ] and indirectly by measurement of isometric systolic tension by means of strain gauge in dogs [ 21 ]. Reduced cardiac output with hyperoxia has even been demonstrated in patients with myocardial infarction using dye injection [ 22 ]. Some of the reduction in cardiac output may be explained by the observation that hyperoxia reduces heart rate as seen in our study and previously [ 19 , 23 - 25 ] Reduced heart rate is, however, not an entirely consistent finding [ 8 , 20 , 22 , 26 ] but in these four studies this could be because of high sympathetic tone (stay in a hyperbaric chamber [ 20 ], acute myocardial infarction [ 22 ], open heart surgery [ 26 ], heart catheterisation [ 8 ]). We found that heart rate increased with hypoxia and decreased with hyperoxia. This might have affected our measures of LV systolic and diastolic function but we consider this unlikely on the basis of our previous studies [ 11 , 27 ] demonstrating that TEI index, strain rate and the tissue tracking was unrelated to heart rate. During hypoxia as well as hyperoxia no change in LV filling pressure was noted as the E/E' ratio was unchanged. The individual parameters in the E/E' ratio are known to be influenced by heart rate but as a ratio it seems independent of heart rate and load conditions [ 11 , 27 ]. Therefore, we did not perform any adjustments for heart rate in the evaluation of LV diastolic function.Because of the finding of no change [ 19 ] or a discrete rise [ 18 , 22 ] in blood pressure, a reduction in cardiac output results in an increased systemic vascular resistance during hyperoxia [ 18 , 19 , 22 ] Regardless of the fact that sympathetic tone may be affected by hyperoxia, even after complete sympathetic blockade myocardial contractile force remains reduced [ 26 ]. In the present study both tissue tracking displacement and strain rate worsened during hyperoxia. It seems plausible that this deterioration could be explained by systemic vasoconstriction [ 21 ] increasing afterload.In conclusion, hypoxia improves and hyperoxia worsens systolic myocardial performance in healthy male volunteers. TDI measures of diastolic function are unaffected by hypoxia/hyperoxia which support that the changes in myocardial performance are secondary to changes in vascular tone. It remains to be settled whether oxygen therapy to patients with heart disease is a rational treatment that may sometimes be harmful or whether supplemental oxygen consistently results in an overall gain in delivered oxygen.


Background Inaccurate malaria results can lead to patient mismanagement, misperceptions about malaria resistance patterns and public health misinformation. All laboratories need to be able to demonstrate that their results are accurate. Establishing and maintaining a system for monitoring test accuracy is a complex, expensive and technically demanding process, which very few poor countries have been able to implement. This study described the process and assessed the feasibility of establishing a nation-wide system for improving the accuracy of malaria-related tests in peripheral laboratories in Ghana.
Background
Inaccurate malaria results can lead to patient mismanagement, misperceptions about malaria resistance patterns and public health misinformation. All laboratories need to be able to demonstrate that their results are accurate. Establishing and maintaining a system for monitoring test accuracy is a complex, expensive and technically demanding process, which very few poor countries have been able to implement. This study described the process and assessed the feasibility of establishing a nation-wide system for improving the accuracy of malaria-related tests in peripheral laboratories in Ghana.Programme implementation A baseline survey of all 693 laboratory staff in 205 sub-regional government and mission health laboratories in Ghana was conducted by a national network of laboratory supervisors. Survey results guided a training programme to improve test accuracy. Outcomes included changes in the quality of laboratory tests and the system was considered to be feasible if >50% of laboratory staff in each region received training and if test accuracy could be documented.
Programme implementation
A baseline survey of all 693 laboratory staff in 205 sub-regional government and mission health laboratories in Ghana was conducted by a national network of laboratory supervisors. Survey results guided a training programme to improve test accuracy. Outcomes included changes in the quality of laboratory tests and the system was considered to be feasible if >50% of laboratory staff in each region received training and if test accuracy could be documented.Programme indicators 74% (mean) of the 693 laboratory staff were assistants with no professional qualifications. There were marked differences between regions in the availability of essential resources for malaria diagnosis (e.g. microscopes). 93% of laboratory staff received training; in six months there were increases of 11% and 7% respectively in the number of laboratories producing haemoglobin and malaria microscopy results of acceptable quality.
Programme indicators
74% (mean) of the 693 laboratory staff were assistants with no professional qualifications. There were marked differences between regions in the availability of essential resources for malaria diagnosis (e.g. microscopes). 93% of laboratory staff received training; in six months there were increases of 11% and 7% respectively in the number of laboratories producing haemoglobin and malaria microscopy results of acceptable quality.Conclusions It is possible to establish a system for improving and monitoring test accuracy in peripheral laboratories on a country-wide basis in a developing country using a model that could be adapted for use in other countries and for other components of health care provision.
Conclusions
It is possible to establish a system for improving and monitoring test accuracy in peripheral laboratories on a country-wide basis in a developing country using a model that could be adapted for use in other countries and for other components of health care provision.

Background Clinical laboratory services are a critical component of health systems. They are essential for patient management and for providing accurate public health data including early detection of malaria resistance. In many poorer countries, laboratory services have been neglected due to chronic under-investment. The emergence of drug-resistant malaria and the extra burden of supporting diagnosis and treatment of HIV/AIDS has increased the strain on laboratories. The widespread resistance of malaria to cheap, antimalarial drugs such as chloroquine and the increasing use of relatively expensive combination therapy, means that presumptive treatment of all fevers as malaria may no longer be a sustainable option for some countries [ 1 ]. It is, therefore, imperative that malaria diagnosis at peripheral level health facilities, where the greatest burden of malaria health care provision is focused, is accurate. Establishing and maintaining an accurate and reliable laboratory service is a complex, expensive and technically demanding process, which very few poor countries have been able to implement. It depends on good laboratory management to oversee processes such as documentation, audit cycles, quality assurance and external validation, safety practices, and supervisory and accountability structures [ 2 ] and should be combined with improvements in clinical practice. Sub-standard laboratory services waste public and individuals' resources and result in clinical mismanagement and inaccurate health information. They also generate a culture of mistrust and communication breakdown between laboratory and clinical staff which contributes to low morale within the technical profession. Poor quality laboratory services have the greatest impact on the poorest people who use the service because they have the largest burden of ill-health [ 3 ]. To our knowledge there is no comprehensive nationwide system for monitoring the accuracy of malaria-related laboratory tests (i.e. malaria microscopy, haemoglobin estimation, tests associated with blood transfusion) currently operational in any sub-Saharan country. In January 2000, the Ministry of Health in Ghana commenced a two-year programme to determine the feasibility of establishing a nationwide quality assurance system for common tests performed at peripheral (district and sub-district) laboratories. This programme was specifically designed to complement the Ministry's 5-year Programme of Work [ 4 ]. In Ghana, laboratory services exist at most levels of health facility, except smaller health centres. Ghana's decentralization policy means that regional and district health managers are responsible for delivering and evaluating health care provision, including laboratory services. Prior to this programme there were no local or national quality assurance systems and no functional supervisory network for laboratories in Ghana. This feasibility programme was built on established laboratory management structures and locally available resources and was implemented by a national network of senior laboratory technicians. The aim of the programme was to determine the feasibility of establishing a nationwide system for improving the accuracy of malaria and other common laboratory tests. All staff performing laboratory tests in all public sector peripheral laboratories in Ghana were included in the programme irrespective of their grade.
Background
Clinical laboratory services are a critical component of health systems. They are essential for patient management and for providing accurate public health data including early detection of malaria resistance. In many poorer countries, laboratory services have been neglected due to chronic under-investment. The emergence of drug-resistant malaria and the extra burden of supporting diagnosis and treatment of HIV/AIDS has increased the strain on laboratories. The widespread resistance of malaria to cheap, antimalarial drugs such as chloroquine and the increasing use of relatively expensive combination therapy, means that presumptive treatment of all fevers as malaria may no longer be a sustainable option for some countries [ 1 ]. It is, therefore, imperative that malaria diagnosis at peripheral level health facilities, where the greatest burden of malaria health care provision is focused, is accurate.Establishing and maintaining an accurate and reliable laboratory service is a complex, expensive and technically demanding process, which very few poor countries have been able to implement. It depends on good laboratory management to oversee processes such as documentation, audit cycles, quality assurance and external validation, safety practices, and supervisory and accountability structures [ 2 ] and should be combined with improvements in clinical practice. Sub-standard laboratory services waste public and individuals' resources and result in clinical mismanagement and inaccurate health information. They also generate a culture of mistrust and communication breakdown between laboratory and clinical staff which contributes to low morale within the technical profession. Poor quality laboratory services have the greatest impact on the poorest people who use the service because they have the largest burden of ill-health [ 3 ]. To our knowledge there is no comprehensive nationwide system for monitoring the accuracy of malaria-related laboratory tests (i.e. malaria microscopy, haemoglobin estimation, tests associated with blood transfusion) currently operational in any sub-Saharan country.In January 2000, the Ministry of Health in Ghana commenced a two-year programme to determine the feasibility of establishing a nationwide quality assurance system for common tests performed at peripheral (district and sub-district) laboratories. This programme was specifically designed to complement the Ministry's 5-year Programme of Work [ 4 ]. In Ghana, laboratory services exist at most levels of health facility, except smaller health centres. Ghana's decentralization policy means that regional and district health managers are responsible for delivering and evaluating health care provision, including laboratory services. Prior to this programme there were no local or national quality assurance systems and no functional supervisory network for laboratories in Ghana. This feasibility programme was built on established laboratory management structures and locally available resources and was implemented by a national network of senior laboratory technicians. The aim of the programme was to determine the feasibility of establishing a nationwide system for improving the accuracy of malaria and other common laboratory tests. All staff performing laboratory tests in all public sector peripheral laboratories in Ghana were included in the programme irrespective of their grade.Programme implementation Establishing a national network of laboratory 'supervisors' Two senior technicians from each of Ghana's ten administrative regions were chosen by the Ministry of Health to constitute the national network of laboratory supervisors who would implement the programme. They were selected on the basis of their geographic location, seniority and commitment to improving laboratory services. All the supervisors had technical qualifications (2–3 years certificate or diploma course), but none had any higher technical or educational qualifications. Programme objective and baseline survey A workshop for the supervisors was held in Ghana at the beginning of the programme to define the objectives and to develop a workplan, timetable and monitoring processes. The agreed programme objective was to establish a system in all peripheral government laboratories in Ghana, for monitoring the accuracy of results of malaria microscopy, haemoglobin estimation and other commonly performed tests. The ability to train over 50% of laboratory staff in each of the ten regions and to monitor changes in the accuracy of results, were used as indicators of programme feasibility. As very little information was available about the state of Ghana's laboratories, supervisors initially carried out a nationwide baseline survey of all Ghana's peripheral laboratory facilities. They personally visited every government and mission laboratory in Ghana and collected first hand information about staff, equipment and tests offered. For each laboratory they also completed a safety checklist based on the World Health Organization's recommendations for laboratory safety [ 5 ]. Programme design and methods Programme planning and training Ideally training should be targeted towards the tests which are performed most poorly. However, as there were no monitoring systems in place in Ghana for laboratory tests and none of Ghana's laboratory staff had had any experience of these systems, it was not possible initially to identify the worst performed tests. The supervisors therefore started by providing training on seven of the most commonly performed tests. They used Ghana's Standard Laboratory Operating Procedures [ 6 ], which describe nationally standardized methods for individual tests, as their core teaching manual. Their choice of teaching methods, predominantly combinations of workshops and workplace training, varied between regions depending on local resources, needs and geography. Monitoring test accuracy Quality assurance systems used in industrialised countries and published in the literature are not appropriate for rural laboratories in poor countries such as Ghana. They are too complex for a workforce that is primarily made up of laboratory assistants and they are based on assumptions that the methods are generally automated and communication and transport networks are reliable. The supervisors therefore had to devise workable methods for externally monitoring test results from the peripheral laboratories. They distributed samples with known values to peripheral laboratories who processed them under normal working conditions. Once the methods for distributing, preserving and measuring test accuracy had been optimized for local use they were piloted in a small number of laboratories, before being introduced throughout each region. The ways in which the test accuracy was determined varied for each test. For example, for haemoglobin estimations a whole blood sample with known value (determined by repeated measurements in a regional laboratory) was distributed to peripheral laboratories and supervisors decided that laboratories with results outside the target value ±10% would receive priority for training. As the quality of results from peripheral laboratories improved, the supervisors reduced the acceptable range of results to ±5% of the target value. For malaria microscopy, the target malaria result of a whole blood sample or malaria smear was determined by consensus of several technicians from the regional hospital. Results from peripheral laboratories were considered 'accurate' if laboratories reported the presence (or absence) of malaria parasites and quantified them to within one grade (on a grading system of 0,+,++,+++) of the target result. For sickle cell tests a blood sample of know sickle status, determined by the regional laboratory, was distributed. Accurate results were those that correctly identified the sample as containing sickle haemoglobin or not. If the majority of results from peripheral laboratories for a single test varied from the target result, the supervisors re-evaluated their test target values. Whole blood samples were distributed in order to check the complete process of testing (e.g. pipetting accuracy, malaria smear preparation) rather than just an individual component. Supervisors used results of the quality monitoring to provide constructive feedback to the laboratory staff and to target their training towards tests and laboratories that performed particularly poorly. Programme funding Initially the programme was funded directly from Ministry of Health headquarters but subsequently, through collaboration with regional Ministry of Health administrators, several supervisors were able to access their own regional funds. Programme indicators Baseline survey There were 205 laboratories in Ghana located in regional and district government hospitals (97), mission hospitals (53) or health centres (54). The total staff complement in these laboratories was 693. The percentage of staff in each of the ten regions with no professional qualifications (assistants or bench-trained with 6 weeks to 1 year training) varied from 60–83% (mean 74%). Even after correcting for differences in regional populations and excluding regions with teaching hospitals, there were wide variations between regions in the number of laboratories and the availability of essential laboratory equipment such as microscopes, (Table  1 ). The safety survey showed that over 50% of 62 laboratories surveyed lacked essential items such as automatic pipettes (necessitating mouth-pipetting) (74%), protocols for waste disposal and equipment maintenance (82% and 100% respectively), first aid kits (100%) and fire safety equipment (94%). Other unsafe practices included allowing patients inside the laboratory (89%) and eating and drinking within the laboratory (55%). Table 1 Regional variations in laboratory resources corrected for population (year 2000) (excluding two regions with teaching hospitals) Region 2 3 4 6 7 8 9 10 Mean Range Population (millions) 2.10 1.55 2.65 2.10 1.25 0.70 1.80 1.85 Laboratories Total 16 15 40 7 26 9 57 32 per 100,000 pop. 0.76 0.97 1.51 0.33 2.08 1.29 3.17 1.73 1.48 0.33–3.17 Trained staff Total 13 9 21 11 11 7 19 24 per 100,000 pop. 0.62 0.58 0.79 0.52 0.88 1.00 1.06 1.30 0.85 0.52–1.30 Microscopes Total 30 20 51 NI 16 6 76 20 per 100,000 pop. 1.40 1.29 1.92 NI 1.28 0.86 4.22 1.08 1.72 0.86–4.22 Colorimeters Total 17 8 46 6 6 5 14 14 per 100,000 pop. 0.81 0.52 1.74 0.29 0.48 0.71 0.78 0.76 1.22 0.52–1.74 Centrifuges Total 20 15 46 12 6 6 54 21 per 100,000 pop. 0.95 7.42 1.74 0.57 0.48 0.86 3.00 1.14 2.02 0.48–7.42 Haematocrit centrifuge Total 9 4 39 7 8 2 5 10 per 100,000 pop. 0.43 0.23 1.47 0.33 0.64 0.29 0.28 0.54 0.53 0.23–1.47 Spectrophotometer Total 5 3 13 2 5 2 3 2 per 100,000 pop. 0.24 0.19 0.49 0.95 0.40 0.29 0.17 0.11 0.39 0.11–0.95 Blood mixer Total 5 3 20 0 0 1 10 0 per 100,000 pop. 0.24 0.19 0.75 0 0 0.14 0.56 0 0.24 0–0.75 NI = no information Extent of training and impact on test accuracy After 18 months, a mean of 93% (regional variation 58%–100%) of all Ghana's laboratory staff had been trained in malaria-related and other common tests. During the final six months of the programme the supervisors monitored the quality of haemoglobin estimations, sickle cell test and malaria microscopy results in 48% of all Ghana's 205 laboratories. In 4 regions the quality of up to 11 tests had been monitored. Tests that gave quantitative results were consistently the most poorly performed tests in all regions with only 78%, 78% and 84% of laboratories producing acceptable results for haemoglobin measurements, white blood counts and malaria microscopy respectively. Tests for HIV, hepatitis B, sickle-cell screen and ZN stain were consistently performed well with over 95% of laboratories meeting agreed target results. After a further six months training there were improvements in the accuracy of several tests, particularly in haemoglobin estimation and malaria microscopy with 89%, 83% and 91% of laboratories producing acceptable results for these tests respectively, (Table  2 ). Table 2 Changes in test accuracy in six months Mean number of laboratories with accurate results/total surveyed (%) Test Month 1 Month 6 Haemoglobin 45/58 (78) 49/58 (89) Malaria microscopy 49/58 (84) 49/54 (91) Sickle screen 53/53 (100) 51/51 (100) White blood count 31/40 (78) 40/48 (83) Blood group 23/24 (96) 57/58 (98) Cross match 7/7 (100) 7/7 (100) HIV test 27/28 (96) 28/28 (100) Hepatitis B antigen 22/22 (100) 40/40 (100) ZN stain 38/39 (97) 39/39 (100)
Programme implementation
Establishing a national network of laboratory 'supervisors' Two senior technicians from each of Ghana's ten administrative regions were chosen by the Ministry of Health to constitute the national network of laboratory supervisors who would implement the programme. They were selected on the basis of their geographic location, seniority and commitment to improving laboratory services. All the supervisors had technical qualifications (2–3 years certificate or diploma course), but none had any higher technical or educational qualifications.
Establishing a national network of laboratory 'supervisors'
Two senior technicians from each of Ghana's ten administrative regions were chosen by the Ministry of Health to constitute the national network of laboratory supervisors who would implement the programme. They were selected on the basis of their geographic location, seniority and commitment to improving laboratory services. All the supervisors had technical qualifications (2–3 years certificate or diploma course), but none had any higher technical or educational qualifications.Programme objective and baseline survey A workshop for the supervisors was held in Ghana at the beginning of the programme to define the objectives and to develop a workplan, timetable and monitoring processes. The agreed programme objective was to establish a system in all peripheral government laboratories in Ghana, for monitoring the accuracy of results of malaria microscopy, haemoglobin estimation and other commonly performed tests. The ability to train over 50% of laboratory staff in each of the ten regions and to monitor changes in the accuracy of results, were used as indicators of programme feasibility. As very little information was available about the state of Ghana's laboratories, supervisors initially carried out a nationwide baseline survey of all Ghana's peripheral laboratory facilities. They personally visited every government and mission laboratory in Ghana and collected first hand information about staff, equipment and tests offered. For each laboratory they also completed a safety checklist based on the World Health Organization's recommendations for laboratory safety [ 5 ].
Programme objective and baseline survey
A workshop for the supervisors was held in Ghana at the beginning of the programme to define the objectives and to develop a workplan, timetable and monitoring processes. The agreed programme objective was to establish a system in all peripheral government laboratories in Ghana, for monitoring the accuracy of results of malaria microscopy, haemoglobin estimation and other commonly performed tests. The ability to train over 50% of laboratory staff in each of the ten regions and to monitor changes in the accuracy of results, were used as indicators of programme feasibility. As very little information was available about the state of Ghana's laboratories, supervisors initially carried out a nationwide baseline survey of all Ghana's peripheral laboratory facilities. They personally visited every government and mission laboratory in Ghana and collected first hand information about staff, equipment and tests offered. For each laboratory they also completed a safety checklist based on the World Health Organization's recommendations for laboratory safety [ 5 ].Programme design and methods Programme planning and training Ideally training should be targeted towards the tests which are performed most poorly. However, as there were no monitoring systems in place in Ghana for laboratory tests and none of Ghana's laboratory staff had had any experience of these systems, it was not possible initially to identify the worst performed tests. The supervisors therefore started by providing training on seven of the most commonly performed tests. They used Ghana's Standard Laboratory Operating Procedures [ 6 ], which describe nationally standardized methods for individual tests, as their core teaching manual. Their choice of teaching methods, predominantly combinations of workshops and workplace training, varied between regions depending on local resources, needs and geography. Monitoring test accuracy Quality assurance systems used in industrialised countries and published in the literature are not appropriate for rural laboratories in poor countries such as Ghana. They are too complex for a workforce that is primarily made up of laboratory assistants and they are based on assumptions that the methods are generally automated and communication and transport networks are reliable. The supervisors therefore had to devise workable methods for externally monitoring test results from the peripheral laboratories. They distributed samples with known values to peripheral laboratories who processed them under normal working conditions. Once the methods for distributing, preserving and measuring test accuracy had been optimized for local use they were piloted in a small number of laboratories, before being introduced throughout each region. The ways in which the test accuracy was determined varied for each test. For example, for haemoglobin estimations a whole blood sample with known value (determined by repeated measurements in a regional laboratory) was distributed to peripheral laboratories and supervisors decided that laboratories with results outside the target value ±10% would receive priority for training. As the quality of results from peripheral laboratories improved, the supervisors reduced the acceptable range of results to ±5% of the target value. For malaria microscopy, the target malaria result of a whole blood sample or malaria smear was determined by consensus of several technicians from the regional hospital. Results from peripheral laboratories were considered 'accurate' if laboratories reported the presence (or absence) of malaria parasites and quantified them to within one grade (on a grading system of 0,+,++,+++) of the target result. For sickle cell tests a blood sample of know sickle status, determined by the regional laboratory, was distributed. Accurate results were those that correctly identified the sample as containing sickle haemoglobin or not. If the majority of results from peripheral laboratories for a single test varied from the target result, the supervisors re-evaluated their test target values. Whole blood samples were distributed in order to check the complete process of testing (e.g. pipetting accuracy, malaria smear preparation) rather than just an individual component. Supervisors used results of the quality monitoring to provide constructive feedback to the laboratory staff and to target their training towards tests and laboratories that performed particularly poorly. Programme funding Initially the programme was funded directly from Ministry of Health headquarters but subsequently, through collaboration with regional Ministry of Health administrators, several supervisors were able to access their own regional funds.
Programme design and methods
Programme planning and training Ideally training should be targeted towards the tests which are performed most poorly. However, as there were no monitoring systems in place in Ghana for laboratory tests and none of Ghana's laboratory staff had had any experience of these systems, it was not possible initially to identify the worst performed tests. The supervisors therefore started by providing training on seven of the most commonly performed tests. They used Ghana's Standard Laboratory Operating Procedures [ 6 ], which describe nationally standardized methods for individual tests, as their core teaching manual. Their choice of teaching methods, predominantly combinations of workshops and workplace training, varied between regions depending on local resources, needs and geography.
Programme planning and training
Ideally training should be targeted towards the tests which are performed most poorly. However, as there were no monitoring systems in place in Ghana for laboratory tests and none of Ghana's laboratory staff had had any experience of these systems, it was not possible initially to identify the worst performed tests. The supervisors therefore started by providing training on seven of the most commonly performed tests. They used Ghana's Standard Laboratory Operating Procedures [ 6 ], which describe nationally standardized methods for individual tests, as their core teaching manual. Their choice of teaching methods, predominantly combinations of workshops and workplace training, varied between regions depending on local resources, needs and geography.Monitoring test accuracy Quality assurance systems used in industrialised countries and published in the literature are not appropriate for rural laboratories in poor countries such as Ghana. They are too complex for a workforce that is primarily made up of laboratory assistants and they are based on assumptions that the methods are generally automated and communication and transport networks are reliable. The supervisors therefore had to devise workable methods for externally monitoring test results from the peripheral laboratories. They distributed samples with known values to peripheral laboratories who processed them under normal working conditions. Once the methods for distributing, preserving and measuring test accuracy had been optimized for local use they were piloted in a small number of laboratories, before being introduced throughout each region. The ways in which the test accuracy was determined varied for each test. For example, for haemoglobin estimations a whole blood sample with known value (determined by repeated measurements in a regional laboratory) was distributed to peripheral laboratories and supervisors decided that laboratories with results outside the target value ±10% would receive priority for training. As the quality of results from peripheral laboratories improved, the supervisors reduced the acceptable range of results to ±5% of the target value. For malaria microscopy, the target malaria result of a whole blood sample or malaria smear was determined by consensus of several technicians from the regional hospital. Results from peripheral laboratories were considered 'accurate' if laboratories reported the presence (or absence) of malaria parasites and quantified them to within one grade (on a grading system of 0,+,++,+++) of the target result. For sickle cell tests a blood sample of know sickle status, determined by the regional laboratory, was distributed. Accurate results were those that correctly identified the sample as containing sickle haemoglobin or not. If the majority of results from peripheral laboratories for a single test varied from the target result, the supervisors re-evaluated their test target values. Whole blood samples were distributed in order to check the complete process of testing (e.g. pipetting accuracy, malaria smear preparation) rather than just an individual component. Supervisors used results of the quality monitoring to provide constructive feedback to the laboratory staff and to target their training towards tests and laboratories that performed particularly poorly.
Monitoring test accuracy
Quality assurance systems used in industrialised countries and published in the literature are not appropriate for rural laboratories in poor countries such as Ghana. They are too complex for a workforce that is primarily made up of laboratory assistants and they are based on assumptions that the methods are generally automated and communication and transport networks are reliable. The supervisors therefore had to devise workable methods for externally monitoring test results from the peripheral laboratories. They distributed samples with known values to peripheral laboratories who processed them under normal working conditions. Once the methods for distributing, preserving and measuring test accuracy had been optimized for local use they were piloted in a small number of laboratories, before being introduced throughout each region. The ways in which the test accuracy was determined varied for each test. For example, for haemoglobin estimations a whole blood sample with known value (determined by repeated measurements in a regional laboratory) was distributed to peripheral laboratories and supervisors decided that laboratories with results outside the target value ±10% would receive priority for training. As the quality of results from peripheral laboratories improved, the supervisors reduced the acceptable range of results to ±5% of the target value. For malaria microscopy, the target malaria result of a whole blood sample or malaria smear was determined by consensus of several technicians from the regional hospital. Results from peripheral laboratories were considered 'accurate' if laboratories reported the presence (or absence) of malaria parasites and quantified them to within one grade (on a grading system of 0,+,++,+++) of the target result. For sickle cell tests a blood sample of know sickle status, determined by the regional laboratory, was distributed. Accurate results were those that correctly identified the sample as containing sickle haemoglobin or not. If the majority of results from peripheral laboratories for a single test varied from the target result, the supervisors re-evaluated their test target values. Whole blood samples were distributed in order to check the complete process of testing (e.g. pipetting accuracy, malaria smear preparation) rather than just an individual component. Supervisors used results of the quality monitoring to provide constructive feedback to the laboratory staff and to target their training towards tests and laboratories that performed particularly poorly.Programme funding Initially the programme was funded directly from Ministry of Health headquarters but subsequently, through collaboration with regional Ministry of Health administrators, several supervisors were able to access their own regional funds.
Programme funding
Initially the programme was funded directly from Ministry of Health headquarters but subsequently, through collaboration with regional Ministry of Health administrators, several supervisors were able to access their own regional funds.Programme indicators Baseline survey There were 205 laboratories in Ghana located in regional and district government hospitals (97), mission hospitals (53) or health centres (54). The total staff complement in these laboratories was 693. The percentage of staff in each of the ten regions with no professional qualifications (assistants or bench-trained with 6 weeks to 1 year training) varied from 60–83% (mean 74%). Even after correcting for differences in regional populations and excluding regions with teaching hospitals, there were wide variations between regions in the number of laboratories and the availability of essential laboratory equipment such as microscopes, (Table  1 ). The safety survey showed that over 50% of 62 laboratories surveyed lacked essential items such as automatic pipettes (necessitating mouth-pipetting) (74%), protocols for waste disposal and equipment maintenance (82% and 100% respectively), first aid kits (100%) and fire safety equipment (94%). Other unsafe practices included allowing patients inside the laboratory (89%) and eating and drinking within the laboratory (55%). Table 1 Regional variations in laboratory resources corrected for population (year 2000) (excluding two regions with teaching hospitals) Region 2 3 4 6 7 8 9 10 Mean Range Population (millions) 2.10 1.55 2.65 2.10 1.25 0.70 1.80 1.85 Laboratories Total 16 15 40 7 26 9 57 32 per 100,000 pop. 0.76 0.97 1.51 0.33 2.08 1.29 3.17 1.73 1.48 0.33–3.17 Trained staff Total 13 9 21 11 11 7 19 24 per 100,000 pop. 0.62 0.58 0.79 0.52 0.88 1.00 1.06 1.30 0.85 0.52–1.30 Microscopes Total 30 20 51 NI 16 6 76 20 per 100,000 pop. 1.40 1.29 1.92 NI 1.28 0.86 4.22 1.08 1.72 0.86–4.22 Colorimeters Total 17 8 46 6 6 5 14 14 per 100,000 pop. 0.81 0.52 1.74 0.29 0.48 0.71 0.78 0.76 1.22 0.52–1.74 Centrifuges Total 20 15 46 12 6 6 54 21 per 100,000 pop. 0.95 7.42 1.74 0.57 0.48 0.86 3.00 1.14 2.02 0.48–7.42 Haematocrit centrifuge Total 9 4 39 7 8 2 5 10 per 100,000 pop. 0.43 0.23 1.47 0.33 0.64 0.29 0.28 0.54 0.53 0.23–1.47 Spectrophotometer Total 5 3 13 2 5 2 3 2 per 100,000 pop. 0.24 0.19 0.49 0.95 0.40 0.29 0.17 0.11 0.39 0.11–0.95 Blood mixer Total 5 3 20 0 0 1 10 0 per 100,000 pop. 0.24 0.19 0.75 0 0 0.14 0.56 0 0.24 0–0.75 NI = no information Extent of training and impact on test accuracy After 18 months, a mean of 93% (regional variation 58%–100%) of all Ghana's laboratory staff had been trained in malaria-related and other common tests. During the final six months of the programme the supervisors monitored the quality of haemoglobin estimations, sickle cell test and malaria microscopy results in 48% of all Ghana's 205 laboratories. In 4 regions the quality of up to 11 tests had been monitored. Tests that gave quantitative results were consistently the most poorly performed tests in all regions with only 78%, 78% and 84% of laboratories producing acceptable results for haemoglobin measurements, white blood counts and malaria microscopy respectively. Tests for HIV, hepatitis B, sickle-cell screen and ZN stain were consistently performed well with over 95% of laboratories meeting agreed target results. After a further six months training there were improvements in the accuracy of several tests, particularly in haemoglobin estimation and malaria microscopy with 89%, 83% and 91% of laboratories producing acceptable results for these tests respectively, (Table  2 ). Table 2 Changes in test accuracy in six months Mean number of laboratories with accurate results/total surveyed (%) Test Month 1 Month 6 Haemoglobin 45/58 (78) 49/58 (89) Malaria microscopy 49/58 (84) 49/54 (91) Sickle screen 53/53 (100) 51/51 (100) White blood count 31/40 (78) 40/48 (83) Blood group 23/24 (96) 57/58 (98) Cross match 7/7 (100) 7/7 (100) HIV test 27/28 (96) 28/28 (100) Hepatitis B antigen 22/22 (100) 40/40 (100) ZN stain 38/39 (97) 39/39 (100)
Programme indicators
Baseline survey There were 205 laboratories in Ghana located in regional and district government hospitals (97), mission hospitals (53) or health centres (54). The total staff complement in these laboratories was 693. The percentage of staff in each of the ten regions with no professional qualifications (assistants or bench-trained with 6 weeks to 1 year training) varied from 60–83% (mean 74%). Even after correcting for differences in regional populations and excluding regions with teaching hospitals, there were wide variations between regions in the number of laboratories and the availability of essential laboratory equipment such as microscopes, (Table  1 ). The safety survey showed that over 50% of 62 laboratories surveyed lacked essential items such as automatic pipettes (necessitating mouth-pipetting) (74%), protocols for waste disposal and equipment maintenance (82% and 100% respectively), first aid kits (100%) and fire safety equipment (94%). Other unsafe practices included allowing patients inside the laboratory (89%) and eating and drinking within the laboratory (55%). Table 1 Regional variations in laboratory resources corrected for population (year 2000) (excluding two regions with teaching hospitals) Region 2 3 4 6 7 8 9 10 Mean Range Population (millions) 2.10 1.55 2.65 2.10 1.25 0.70 1.80 1.85 Laboratories Total 16 15 40 7 26 9 57 32 per 100,000 pop. 0.76 0.97 1.51 0.33 2.08 1.29 3.17 1.73 1.48 0.33–3.17 Trained staff Total 13 9 21 11 11 7 19 24 per 100,000 pop. 0.62 0.58 0.79 0.52 0.88 1.00 1.06 1.30 0.85 0.52–1.30 Microscopes Total 30 20 51 NI 16 6 76 20 per 100,000 pop. 1.40 1.29 1.92 NI 1.28 0.86 4.22 1.08 1.72 0.86–4.22 Colorimeters Total 17 8 46 6 6 5 14 14 per 100,000 pop. 0.81 0.52 1.74 0.29 0.48 0.71 0.78 0.76 1.22 0.52–1.74 Centrifuges Total 20 15 46 12 6 6 54 21 per 100,000 pop. 0.95 7.42 1.74 0.57 0.48 0.86 3.00 1.14 2.02 0.48–7.42 Haematocrit centrifuge Total 9 4 39 7 8 2 5 10 per 100,000 pop. 0.43 0.23 1.47 0.33 0.64 0.29 0.28 0.54 0.53 0.23–1.47 Spectrophotometer Total 5 3 13 2 5 2 3 2 per 100,000 pop. 0.24 0.19 0.49 0.95 0.40 0.29 0.17 0.11 0.39 0.11–0.95 Blood mixer Total 5 3 20 0 0 1 10 0 per 100,000 pop. 0.24 0.19 0.75 0 0 0.14 0.56 0 0.24 0–0.75 NI = no information
Baseline survey
There were 205 laboratories in Ghana located in regional and district government hospitals (97), mission hospitals (53) or health centres (54). The total staff complement in these laboratories was 693. The percentage of staff in each of the ten regions with no professional qualifications (assistants or bench-trained with 6 weeks to 1 year training) varied from 60–83% (mean 74%). Even after correcting for differences in regional populations and excluding regions with teaching hospitals, there were wide variations between regions in the number of laboratories and the availability of essential laboratory equipment such as microscopes, (Table  1 ). The safety survey showed that over 50% of 62 laboratories surveyed lacked essential items such as automatic pipettes (necessitating mouth-pipetting) (74%), protocols for waste disposal and equipment maintenance (82% and 100% respectively), first aid kits (100%) and fire safety equipment (94%). Other unsafe practices included allowing patients inside the laboratory (89%) and eating and drinking within the laboratory (55%).Regional variations in laboratory resources corrected for population (year 2000) (excluding two regions with teaching hospitals)Region234678910MeanRangePopulation (millions)Laboratories1.480.33–3.17Trained staff0.850.52–1.30Microscopes1.720.86–4.22Colorimeters1.220.52–1.74Centrifuges2.020.48–7.42Haematocrit centrifuge0.530.23–1.47Spectrophotometer0.390.11–0.95Blood mixer0.240–0.75NI = no informationExtent of training and impact on test accuracy After 18 months, a mean of 93% (regional variation 58%–100%) of all Ghana's laboratory staff had been trained in malaria-related and other common tests. During the final six months of the programme the supervisors monitored the quality of haemoglobin estimations, sickle cell test and malaria microscopy results in 48% of all Ghana's 205 laboratories. In 4 regions the quality of up to 11 tests had been monitored. Tests that gave quantitative results were consistently the most poorly performed tests in all regions with only 78%, 78% and 84% of laboratories producing acceptable results for haemoglobin measurements, white blood counts and malaria microscopy respectively. Tests for HIV, hepatitis B, sickle-cell screen and ZN stain were consistently performed well with over 95% of laboratories meeting agreed target results. After a further six months training there were improvements in the accuracy of several tests, particularly in haemoglobin estimation and malaria microscopy with 89%, 83% and 91% of laboratories producing acceptable results for these tests respectively, (Table  2 ). Table 2 Changes in test accuracy in six months Mean number of laboratories with accurate results/total surveyed (%) Test Month 1 Month 6 Haemoglobin 45/58 (78) 49/58 (89) Malaria microscopy 49/58 (84) 49/54 (91) Sickle screen 53/53 (100) 51/51 (100) White blood count 31/40 (78) 40/48 (83) Blood group 23/24 (96) 57/58 (98) Cross match 7/7 (100) 7/7 (100) HIV test 27/28 (96) 28/28 (100) Hepatitis B antigen 22/22 (100) 40/40 (100) ZN stain 38/39 (97) 39/39 (100)
Extent of training and impact on test accuracy
After 18 months, a mean of 93% (regional variation 58%–100%) of all Ghana's laboratory staff had been trained in malaria-related and other common tests. During the final six months of the programme the supervisors monitored the quality of haemoglobin estimations, sickle cell test and malaria microscopy results in 48% of all Ghana's 205 laboratories. In 4 regions the quality of up to 11 tests had been monitored. Tests that gave quantitative results were consistently the most poorly performed tests in all regions with only 78%, 78% and 84% of laboratories producing acceptable results for haemoglobin measurements, white blood counts and malaria microscopy respectively. Tests for HIV, hepatitis B, sickle-cell screen and ZN stain were consistently performed well with over 95% of laboratories meeting agreed target results. After a further six months training there were improvements in the accuracy of several tests, particularly in haemoglobin estimation and malaria microscopy with 89%, 83% and 91% of laboratories producing acceptable results for these tests respectively, (Table  2 ).Changes in test accuracy in six monthsMean number of laboratories with accurate results/total surveyed (%)TestMonth 1Month 6Discussion There is very little information available about the state and quality of laboratory services in peripheral health facilities in poorer countries. The baseline survey showed that in Ghana three quarters of public sector laboratory staff do not have any technical qualifications, and even the supervisory cadre only have Diplomas. Through this study we have shown that the lack of professional qualifications amongst the laboratory workforce and the inequitable distribution of laboratory equipment, are not obstacles to establishing a simple and far-reaching quality assurance process. This study has shown that the worst performed tests at sub-regional level are those that generate quantitative or subjective results (such as haemoglobin estimation and malaria microscopy) rather than simple 'positive' or 'negative' results (such as HIV and hepatitis B screening tests). Further research is needed to examine the cost-effectiveness of potentially more accurate or less complex tests (e.g. malaria rapid diagnostic tests, HemoCue). Although these tests may be more expensive than those in use in most districts, their simplicity and accuracy may save downstream costs. One of the major limitations of this study is the lack of quality assurance at regional and supra-regional level for common laboratory tests. These were the laboratories responsible for determining the target values of tests distributed to peripheral laboratories. To overcome this problem, regional laboratories tested the samples several times before determining the target values and they also exchanged samples with each other as an inter-regional check on results. Plans are in place to expand this into an inclusive national quality monitoring system for higher level laboratories. We have confirmed previous work showing that at peripheral health facilities haemoglobin using manual methods is the most inaccurate test [ 7 ]. Safety issues are often not a priority for laboratories in poorer countries but overcrowding and poor laboratory organisation are recognized to be associated with a significant risk of accidents and consequent infection of health workers. Many of the safety issues identified through this project could be easily and cheaply rectified but because there was no supervisory system in place they had been ignored. To our knowledge this is the first external laboratory quality assurance programme in sub-Saharan Africa to demonstrate that it is feasible to achieve widespread coverage of peripheral health laboratories and staff. Through this programme an effective and practical model has been developed for improving the accuracy of common laboratory tests in Ghana. The model is based on a national network of senior technicians who implemented and supervised a continuous cycle of test monitoring and targeted training for all laboratory staff in their regions. The programme's success was dependent on the quality and commitment of the national network of laboratory supervisors. Participation in the programme was itself a strong motivational force for the supervisors. Because of the supportive attitude of the supervisors, the laboratory staff viewed the monitoring visits as educational rather than punitive and this ensured cooperation when remedial action was required. Health planners can use the lessons learnt from this programme to introduce measures to improve morale and job satisfaction of key health workers especially those in the neglected laboratory services. Components of this model have already been adopted by other countries for their laboratory programmes and could be adapted for other health disciplines in poorer countries. Several steps are necessary before this model could be sustainably implemented. The network of supervisors needs to have pro-active long-term support from all stakeholders, combined with career and promotion packages. Health managers need to provide secure funding for laboratory quality assurance programmes at all levels. This includes establishing internal quality control measures and external validation systems that are linked into national and international external quality monitoring schemes. To be successful, this model will require prioritization of the laboratory service by policy makers at national and supra-national level and adequate representation of the laboratories in decision-making processes. Implementing a quality assurance system for laboratories in poorer countries is expensive and logistically complicated. Managers will need to balance cost against quality, taking into account that it is those who are most vulnerable to ill health who can least afford to bear the brunt of the consequences of inaccurate laboratory results.
Discussion
There is very little information available about the state and quality of laboratory services in peripheral health facilities in poorer countries. The baseline survey showed that in Ghana three quarters of public sector laboratory staff do not have any technical qualifications, and even the supervisory cadre only have Diplomas. Through this study we have shown that the lack of professional qualifications amongst the laboratory workforce and the inequitable distribution of laboratory equipment, are not obstacles to establishing a simple and far-reaching quality assurance process.This study has shown that the worst performed tests at sub-regional level are those that generate quantitative or subjective results (such as haemoglobin estimation and malaria microscopy) rather than simple 'positive' or 'negative' results (such as HIV and hepatitis B screening tests). Further research is needed to examine the cost-effectiveness of potentially more accurate or less complex tests (e.g. malaria rapid diagnostic tests, HemoCue). Although these tests may be more expensive than those in use in most districts, their simplicity and accuracy may save downstream costs. One of the major limitations of this study is the lack of quality assurance at regional and supra-regional level for common laboratory tests. These were the laboratories responsible for determining the target values of tests distributed to peripheral laboratories. To overcome this problem, regional laboratories tested the samples several times before determining the target values and they also exchanged samples with each other as an inter-regional check on results. Plans are in place to expand this into an inclusive national quality monitoring system for higher level laboratories.We have confirmed previous work showing that at peripheral health facilities haemoglobin using manual methods is the most inaccurate test [ 7 ]. Safety issues are often not a priority for laboratories in poorer countries but overcrowding and poor laboratory organisation are recognized to be associated with a significant risk of accidents and consequent infection of health workers. Many of the safety issues identified through this project could be easily and cheaply rectified but because there was no supervisory system in place they had been ignored.To our knowledge this is the first external laboratory quality assurance programme in sub-Saharan Africa to demonstrate that it is feasible to achieve widespread coverage of peripheral health laboratories and staff. Through this programme an effective and practical model has been developed for improving the accuracy of common laboratory tests in Ghana. The model is based on a national network of senior technicians who implemented and supervised a continuous cycle of test monitoring and targeted training for all laboratory staff in their regions. The programme's success was dependent on the quality and commitment of the national network of laboratory supervisors. Participation in the programme was itself a strong motivational force for the supervisors. Because of the supportive attitude of the supervisors, the laboratory staff viewed the monitoring visits as educational rather than punitive and this ensured cooperation when remedial action was required. Health planners can use the lessons learnt from this programme to introduce measures to improve morale and job satisfaction of key health workers especially those in the neglected laboratory services. Components of this model have already been adopted by other countries for their laboratory programmes and could be adapted for other health disciplines in poorer countries.Several steps are necessary before this model could be sustainably implemented. The network of supervisors needs to have pro-active long-term support from all stakeholders, combined with career and promotion packages. Health managers need to provide secure funding for laboratory quality assurance programmes at all levels. This includes establishing internal quality control measures and external validation systems that are linked into national and international external quality monitoring schemes. To be successful, this model will require prioritization of the laboratory service by policy makers at national and supra-national level and adequate representation of the laboratories in decision-making processes. Implementing a quality assurance system for laboratories in poorer countries is expensive and logistically complicated. Managers will need to balance cost against quality, taking into account that it is those who are most vulnerable to ill health who can least afford to bear the brunt of the consequences of inaccurate laboratory results.Authors' contributions IB and VB designed the outline framework for the programme. IB documented and collated results. VB was the local programme coordinator. AAA provided an overview and ensured the programme was compatible with Ministry of Health policies. All authors read and approved the final manuscript.
Authors' contributions
IB and VB designed the outline framework for the programme. IB documented and collated results. VB was the local programme coordinator. AAA provided an overview and ensured the programme was compatible with Ministry of Health policies. All authors read and approved the final manuscript.Funding sources This study was supported by the Ministry of Health in Ghana and the Malaria Knowledge Programme (funded by the Department for International Development, UK) at the Liverpool School of Tropical Medicine. The Department for International Development had no role in study design, the collection, analysis and interpretation of data, in the writing of the report or in the decision to submit the paper for publication and accepts no responsibility for the information or views expressed.
Funding sources
This study was supported by the Ministry of Health in Ghana and the Malaria Knowledge Programme (funded by the Department for International Development, UK) at the Liverpool School of Tropical Medicine. The Department for International Development had no role in study design, the collection, analysis and interpretation of data, in the writing of the report or in the decision to submit the paper for publication and accepts no responsibility for the information or views expressed.