Prodromal symptoms of rheumatoid arthritis in a primary care database: variation by ethnicity and socioeconomic status

OBJECTIVES

To assess whether prodromal symptoms of rheumatoid arthritis (RA), as recorded in the Clinical Practice Research Datalink Aurum (CPRD) database of English primary care records, differ by ethnicity and socioeconomic status.

METHODS

A cross-sectional study to determine the coding of common symptoms (≥0.1% in the sample) in the 24 months preceding RA diagnosis in CPRD Aurum, recorded between January 1st 2004 to May 1st 2022. Eligible cases were adults with a code for RA diagnosis. For each symptom, a logistic regression was performed with the symptom as dependent variable, and ethnicity and socioeconomic status as independent variables. Results were adjusted for sex, age, BMI, and smoking status. White ethnicity and the highest socioeconomic quintile were comparators.

RESULTS

In total, 70115 cases were eligible for inclusion, of which 66.4% female. Twenty-one symptoms were coded in > 0.1% of cases so were included in the analysis. Patients of South Asian ethnicity had higher frequency of codes for several symptoms, with the largest difference by odds ratio being muscle cramps (OR 1.71, 1.44-2.57) and shoulder pain (1.44, 1.25-1.66). Patients of Black ethnicity had higher prevalence of several codes including unintended weight loss (2.02, 1.25-3.28) and ankle pain (1.51, 1.02-2.23). Low socioeconomic status was associated with morning stiffness (1.74, 1.08-2.80) and falls (1.37, 2.03-1.82).

CONCLUSION

There are significant differences in coded symptoms between demographic groups, which must be considered in clinical practice in diverse populations and to avoid algorithmic bias in prediction tools derived from routinely collected healthcare data.

Is symptom duration before DMARD therapy a determinant of direct and indirect costs in DMARD-naïve RA patients? A systematic review

Objective

Early treatment of RA improves clinical outcomes; however, the impact on health economic outcomes is unclear. This review sought to investigate the relationship between symptom/disease duration and resource utilization/costs and the responsiveness of costs following RA diagnosis.

Methods

A systematic search was performed on Pubmed, EMBASE, CINAHL and Medline. Studies were eligible if patients were DMARD-naïve and fulfilled 1987 ACR or 2010 ACR/EULAR RA classification criteria. Studies had to report symptom/disease duration and resource utilization or direct/indirect costs as health economic outcomes. The relationships between symptom/disease duration and costs were explored.

Results

Three hundred and fifty-seven records were identified in a systematic search; nine were eligible for analysis. The mean/median of symptom/disease duration in studies ranged between 25 days and 6 years. Annual direct costs of RA following diagnosis showed a U-shaped distribution in two studies. Longer symptom duration before starting a DMARD (>180 days) was associated with lower health-care utilization in the first year of RA diagnosis in one study. Annual direct and indirect costs 6 months before RA diagnosis were higher in patients with shorter symptom duration (<6 months) in one study. Given the clinical and methodological heterogeneities, the association between symptom/disease duration and costs after diagnosis was not computed.

Conclusion

The association between symptom/disease duration at the time of DMARD initiation and resource utilization/cost in patients with RA remains unclear. Health economic modelling with clearly defined symptom duration, resource utilization and long-term productivity is vital to address this evidence gap.