In this northern Tanzanian pilot study, we found a prevalence of GALS/pGALS positivity of 8.1% and REMS positivity of 3.2% in this household enrolled population. To our knowledge, this is the first time the locally adapted GALS/pGALS and REMS tools have been used to quantify the prevalence of MSK disorders in a community setting in northern Tanzania. The practicality of the pGALS English version for use in a Malawian hospital (similar setting) was found to be good with high acceptability [24]. These initial prevalence estimates, generated with slightly modified tools, indicate a burden of MSK disorders in the rural Tanzanian population that is similar to the overall prevalence estimate generated by the global burden of disease study 2010 [11]. This initial prevalence estimate provides a strong rationale for the need for further investigation of the burden of MSK disorders in this context. These data can inform the design of future studies of the burden, impacts and clinical aetiologies associated with MSK disorders in Tanzania and inform health service planning.
The GALS/pGALS and REMS tools are used during physical examinations to detect MSK abnormalities and cannot be used alone to diagnose clinical conditions such as arthritis. However, they are valuable to help identify possible arthritis cases and inform further investigations. Diagnosing specific MSK and arthritis conditions requires clinical history, physical examination, laboratory and radiological investigations, and exclusion of other potential causes for the presentation [22, 24, 25, 27, 28]. Therefore, we encounter challenges in drawing inferences about the causation of these MSK impairments. To achieve specific diagnosis additional investigative data are needed.
In this study age and gender were both found to have an association with GALS/pGALS and REMS status. Female and older individuals were more likely to have positive GALS/pGALS and REMS status. These findings agree with many previous studies conducted in other countries where age and gender have been seen to have a positive association with several MSK disorders field[5, 14, 28, 29]. There were seven pGALS positives observed from the school enrolled population and just four pGALS positives were identified from the household enrolled population aged between 5 and 17 years. We identified 19 GALS positives individuals aged 18 to 54 years Table 3. These MSK disorders in the working-age populations could impact the local and national economy [30, 31]. In many studies MSK disorders are associated with older ages however, there are some populations where MSK disorders are found to extend to younger ages though they are still much more common in the older ages [29, 32, 33]. Investigation of modifiable factors associated with MSK disorders was beyond the scope of this study. We recommend that future studies consider the contribution of external modifiable factors to the risk of MSK disorders and evaluate the influence of factors including occupation, lifestyle, obesity, diet, mobility, education, marital status and climate on the probability of MSK disorders in this population as done by other studies [28, 31, 33–35].
The majority (90.2%) of GALS/pGALS positive participants had normal or mild functional loss as determined using the MHAQ tool with the previously published scaling and categorisation, with the remaining 9.8% of GALS/pGALS positive participants showing moderate to severe functional loss. Minor changes were made to the MHAQ tool for application in this Tanzanian population. These were very minor as compared to the published tool, but it is possible that these changes may have minor influences on the classifications reported and thus the comparability of these data to those from other studies. Previous studies have identified age and gender as important predictors not only for arthritis but also for related treatment outcomes [34, 36]. We found an association between increased age and higher MHAQ scores, which reflects a greater loss of function within older age groups. This finding is similar to findings in high-income contexts, such as the USA [9, 28].
From this pilot study, we learned valuable lessons to inform future community studies in northern Tanzania. The school enrolled participants had higher proportions of missing data and only very few GALS/pGALS positive individuals were identified from schools Table 3. We, therefore, recommend that future studies consider aiming to enrol children in their households at their convenient time rather than through schools. We also observed that the GALS/pGALS, REMS and MHAQ tools with minor adaption and appropriate training can be easily applied in rural Tanzania. Lessons learned from this pilot study, based on field observation and experience, and discussion within the study team also indicate that GALS/pGALS is likely to classify some individuals with non-MSK conditions as positive, with important implications for interpretation of prevalence studies. For example, the GALS/pGALS positive population identified in this study included a small number of individuals with neuropathic disorders (paraplegia, paralysis, paraesthesia) and amputations. Future studies could include additional questions to complement the use of the GALS/pGALS tool to enable the exclusion of individuals who are classified as GALS/pGALS positive for reasons other than underlying MSK disorders such as arthritis. The administration of GALS and REMS tools was also observed to cause discomfort in some participants. If the screening process is not properly thought through and explained, some participants might be reluctant to undertake some of the manoeuvres and therefore not be able to complete the examinations.
This was a small scale pilot study and we cannot extrapolate findings from this study and generalize them to a wider population. Therefore, a wider scale systematic survey is recommended, which should also consider radiological and laboratory investigation to establish specific aetiologies of joint pain. We also recommend that future investigations could also include an assessment of the quality of life impacts of MSK disorders, increased direct and indirect cost of illness and health care utilisation, and increased dependency on other people (relatives friends and community) [37].