Sensitivity and specificity of routine diagnostic work-up for tuberculosis in lung clinics in Yogyakarta, Indonesia: a cohort study.
BACKGROUND
Establishing a correct diagnosis is challenging. We aimed to investigate the sensitivity and specificity of routine tuberculosis (TB) diagnostic work-up in lung clinics in Indonesia, a country with the third highest TB burden and the second highest gap between notifications of TB cases and the best estimate of incident cases in the world.


METHODS
In the lung clinics of the Province of Yogyakarta, Indonesia, we recruited all consecutive patients with symptoms suggesting TB, aged ≥18 years. Routine TB examination consisted of clinical evaluation, sputum smear microscopy, and chest radiography. For research purposes, we added sputum culture, Human Immunodeficiency Virus (HIV) testing, and follow-up for 1.5 years or 2.5 years if culture results disagreed with the initial clinical diagnosis. The initial diagnosis was considered incorrect if patients did not respond to treatment. We calculated sensitivity and specificity of the TB routine examination using culture and a composite reference standard (CRS - a combination of routine examination, culture, and follow-up) as the reference standards. All analyses were conducted with IBM SPSS Statistics 25 (IBM Corp., Armonk, NY, USA).


RESULTS
Between 2013 and 2015, we included 360 participants, and 21 were excluded due to incomplete data. Among those analyzed, 115 were initially diagnosed with smear-positive TB, 12 with smear-negative TB, and 212 non-TB. In 15 study participants, the diagnosis was changed after median 45 (range: 14-870) days; 14 participants initially not diagnosed with TB were later diagnosed with TB, while one subject initially diagnosed with TB actually did not have TB. Compared with culture and CRS, TB routine examination had sensitivity of 85% (95%CI: 77-91) and 90% (95%CI: 84-94), and specificity of 86.3% (95%CI: 81-91) and 99.5% (95%CI: 97-100), respectively.


CONCLUSIONS
A combination of clinical evaluation with sputum microscopy and chest radiography provided high sensitivity and specificity in diagnosing TB in lung clinics; in only 4.4% the diagnosis was incorrect. There is a need to improve routine TB diagnostic work by using clinical evaluation, sputum smear microscopy, and chest radiography all together in other settings, such as in primary health centers.


TRIAL REGISTRATION
NCT02219945 , clinicaltrials.gov . Registered 19 August 2014 (retrospectively registered).
['Saktiawati|Antonia Morita I|AMI|http://orcid.org/0000-0001-5896-0846', 'Subronto|Yanri W|YW|', 'Stienstra|Ymkje|Y|', 'Sumardi|||', 'Supit|Fabiola|F|', 'van der Werf|Tjip S|TS|']
D000328:Adult D003955:Diagnostic Tests, Routine D005260:Female D015658:HIV Infections D006801:Humans D007214:Indonesia D008168:Lung D008297:Male D008853:Microscopy D008875:Middle Aged D009169:Mycobacterium tuberculosis D011014:Pneumonia D011859:Radiography D012015:Reference Standards D012189:Retrospective Studies D012680:Sensitivity and Specificity D013183:Sputum D013909:Thorax D014376:Tuberculosis D014397:Tuberculosis, Pulmonary
Sensitivity Specificity Tuberculosis Diagnosis Microscopy Radiography Culture