The test-retest reliability of the lower extremity functional scale in HIV-related distal sensory peripheral neuropathy

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the Degree of Master of Science (Physiotherapy). Johannesburg, 2018.Background: The Human Immunodeficiency Virus (HIV) and the Acquired Immune Deficiency Syndrome (AIDS) have posed a serious disease burden on society. The side effects issuing from the anti`-retroviral drugs (ARVs) include Distal Sensory Peripheral Neuropathy (DSPN), a common neurological complication. The Lower Extremity Functional Scale (LLFS) is a reliable and valid tool that has been used for measuring the lower limb functional capacity of patients presenting with DSPN in countries other than Botswana. As such, it is necessary to test its test-retest reliability in Botswana. Aim: The aim of this study was to determine the test-retest reliability of the Lower Extremity Functional Scale (LEFS) among HIV-related DSPN patients in Botswana. Methodology: This study involved a test-retest reliability study based on a time interval of seven to 10 days. A total of 320 HIV patients from six hospitals in Gaborone, Botswana, were screened for DSPN according to the relevant inclusion and exclusion criteria .The percentage of the total patients who were diagnosed with DSPN was 26.3% (84). The lower extremity functional scale LEFS questionnaire was administered twice with a seven to 10-day period interval and the results of the assessment were recorded and analysed. Measurements of central tendencies were used to summarize the demographic data and the clinical information for the lower extremity functional scale information obtained. Because the data sets were categorical, Spearman’s correlation analysis was conducted to determine the efficacy of the test-retest reliability. Furthermore, the Intraclass correlation (ICC) was used for measuring the internal consistency of the LEFS questionnaire. Demographic data such as age, gender, education and marital status, and clinical information pertaining to the participants were used to describe them. Results: A total of 84 HIV patients from six hospitals who were on anti-retroviral therapy (ART) and presenting with DSPN participated in the study. The test-retest reliability was found to range from rs=0.74-0.99, ICC = 0.96. SEM=4.88 Conclusion: The study results showed strong test-retest reliability and good internal consistency. Hence, the LEFS questionnaire can be considered reliable as a standard from which to monitor lower limb functionality in HIV-related Distal Sensory Peripheral Neuropathy among patients in Botswana.LG201