Development and evaluation of the medication-based index of physical function (MedIP).
Background
the development of an objective and comprehensive drug-based index of physical function for older adults has the potential to more accurately predict fall risk.


Design
the index was developed using 862 adults (ages 57-85) from the National Social Life, Health, and Aging Project (NSHAP) Wave 1 study. The index was evaluated in 70 adults (ages 51-88) from a rehabilitation study of dizziness and balance.


Methods
the prevalence among 601 drugs for 1,694 side effects was used with fall history to determine the magnitude of each side effect's contribution towards physical function. This information was used to calculate a Medication-based Index of Physical function (MedIP) score for each individual based on his or her medication profile. The MedIP was compared to the timed up and go (TUG) test as well as drug counts using receiver operating characteristic (ROC) analysis. The associations between various indices of physical function and MedIP were calculated.


Results
within the NSHAP data set, the MedIP was better than drug counts or TUG at predicting falls based on ROC analysis. Using scores above and below the cutpoint, the MedIP was a significant predictor of falls (OR = 2.61 [95% CI 1.83, 3.64]; P < 0.001). Using an external data set, it was shown that the MedIP was significantly correlated with fall number (P = 0.044), composite physical function (P = 0.026) and preferred gait speed (P = 0.043).


Conclusion
the MedIP has the potential to become a useful tool in the healthcare and fall prevention of older individuals.
['Hall|Courtney D|CD|', 'Karpen|Samuel C|SC|', 'Odle|Brian|B|', 'Panus|Peter C|PC|', 'Walls|Zachary F|ZF|']
D000058:Accidental Falls D000367:Age Factors D000368:Aged D000369:Aged, 80 and over D000375:Aging D019540:Area Under Curve D064420:Drug-Related Side Effects and Adverse Reactions D005260:Female D005684:Gait D015577:Geriatric Assessment D006305:Health Status Indicators D006801:Humans D008297:Male D008875:Middle Aged D009043:Motor Activity D019338:Polypharmacy D011237:Predictive Value of Tests D015995:Prevalence D012372:ROC Curve D018570:Risk Assessment D012307:Risk Factors D014481:United States
medication-based index of physical function physical function timed up and go fall prevention drug index older people