Lost to follow-up: Challenges to conducting orthopaedic research in South Africa.

Loss to follow-up poses a major problem for clinicians and researchers, and several factors that may increase its risk have been postulated. The objective of this study was to describe potential factors that contribute to loss to follow-up as seen in orthopaedic patients participating in a research study and attending the sole public orthopaedic service provider in the Northern Cape Province of South Africa (SA). All patients who underwent ankle fracture surgery at Kimberley Provincial Hospital between January 2012 and July 2013 were included, and the number of follow-up visits attended by each participant was recorded prospectively. Demographic information pertaining to travel distance, social circumstances and comorbid conditions was captured and reviewed. A total of 268 patients (male n=112, 41.8% and female n=156, 58.2%) were included. The mean (standard deviation (SD)) age was 42.3 (13.8) years (95% confidence interval (CI) 40.6 - 43.9, n=266) and the mean body mass index (BMI, kg/m2) was 28.0 (6.5) (95% CI 27.2 - 28.8, n=251), the BMI for females being 30.2 (6.1) (95% CI 29.3 - 31.2, n=152) compared with 24.6 (5.7) (95% CI 23.4 - 25.7, n=99) for males. After excluding local patients living within 5 km of the hospital (n=77), the mean travel distance was 460 km (range 10 - 910). There was a significant association between the number of follow-up visits attended and travel distance (incidence rate ratio (IRR) 0.999, 95% CI 0.999 - 1.000; p=0.030), BMI (IRR 0.980, 95% CI 0.966 - 0.994; p=0.004) and HIV status (IRR 0.841, 95% CI 0.725 - 0.975; p=0.022). The main factors identified in this study that influenced the number of follow-up visits attended were travel distance, BMI and HIV status. BMI was a unique finding in our study. It was identified to be a significant contributing factor to the loss to follow-up. BMI was not a contributing factor in other studies.