According to the results of a systematic literature review published in Arthritis Care & Research, grip strength, disease activity, and pain were identified as the primary mediators of hand function in patients with rheumatoid arthritis (RA).
Investigators performed a literature search across 6 medical databases for peer-reviewed observational studies concerning hand function in individuals with RA. As further inclusion criteria, studies had to report functional disability outcome measures using either self-report or objective measures commonly used for rheumatic diseases. Additionally, each study captured hand-related activity limitations and provided psychometric support for patients. The methodologic quality of each article was assessed using a critical appraisal checklist for cross-sectional studies (AXIS). The AXIS assesses study design quality and risk for biases; studies with a score exceeding (≥60%) on the AXIS were considered “high quality.” A total of 1254 citations were retrieved using primary search terms, from which 20 articles were selected for review. A best-evidence synthesis review procedure was used to assess the evidence level for each association.
The selected articles presented a mix of cross-sectional (n=15), case-control (n=2), and cohort (n=3) designs. However, each case-control and cohort study presented cross-sectional data regarding factors contributing to hand function. As such, all articles were considered to be cross-sectional. The mean AXIS score of included articles was 49.5%, with 5 articles meeting the threshold for high quality (≥60%). According to the best-evidence synthesis procedure, a wide range of positive and negative factors were found to contribute to hand function. Specifically, limited hand activity was associated with lower hand and grip strength, higher disease activity, and higher pain intensity. However, evidence for these correlations was “limited,” or present in only a single cohort study, a maximum of 2 case-control studies, or in multiple cross-sectional studies. Conflicting evidence was found for the association between age and hand function, in that fewer than 75% of the synthesized articles reported consistent findings. Of the 20 studies, 7 reported no statistically significant difference in hand function between men and women.
Although evidence levels were limited, this literature review identified several key influences on hand function in patients with RA. The limited number of studies reporting on sociodemographic factors, including sex, suggests that clinical research on RA is limited in these areas.
Alkabeya HA, Hughes A-M, Adams J. Factors associated with hand and upper arm functional disability in people with rheumatoid arthritis: A systematic review [published online October 15, 2018]. Arthritis Care Res. doi:10.1002/acr.23784