Abstract
Physical function is the physical ability to fulfill one's daily roles and responsibilities. Poor physical function is detrimental to health and income-generating activities. Unfortunately, there is a lack of validated methods to measure physical function in adult women in low- and middle-income countries, including Ethiopia, the locus of this study. This study evaluated the feasibility, reliability, and validity of physical tests, including the sit-to-stand (STS) and usual gait speed (UGS) and a context-appropriate instrumental activities of daily living (IADL) survey. The results of the STS were used to calculate a muscle quality index (MQI, STS accounting for body mass and leg length). Feasibility was ascertained qualitatively based on reports from the enumerators on their ability to administer the tests. Reliability was assessed by comparing the results of the tests and questions between each visit using either Cohen's κ or Pearson's ρ. The validity of MQI was assessed using relevant participant characteristics such as age and self-reported disability. The validity of the IADL was assessed using MQI. Study participants comprised 316 women between the ages of 18 and 45 years, living in rural Tigray, Ethiopia, who had previously participated in an impact evaluation of a safety net program. Over a one-week period, participants completed the STS and UGS tests and responded to the IADL survey questions three times. MQI was determined to be a feasible, reliable, and valid physical function test for women in rural, highland Ethiopia. UGS lacked feasibility and reliability; validity was not ascertained. The IADL questions were feasible and reliable, but validity was inconclusive. In rural Ethiopia, the MQI will be a valuable tool to develop interventions for improving physical function, which will have positive impacts on health and quality of life.