Medication Cost Concerns and Disparities in Patient-Reported Outcomes Among a Multiethnic Cohort of Patients With Systemic Lupus Erythematosus

Reporting of determinants of health inequities and participant characteristics in randomized controlled trials of systemic lupus erythematosus in Canada: A scoping review

OBJECTIVE

To report participant characteristics relevant to identifying health inequities in systemic lupus erythematosus (SLE) randomized controlled trials conducted in Canada.

METHODS

We conducted a scoping review by searching MEDLINE (Ovid) and Embase (1990 to June 2023), and CENTRAL (inception to June 2023). Eligible studies: used an RCT design; evaluated interventions (pharmacologic and non-pharmacologic) among SLE patients aged ≥18 years; and were conducted in Canada. Data extraction was guided by the Campbell and Cochrane Equity Methods Group's PROGRESS-Plus framework on 11 factors leading to health inequities (Place of residence; Race, culture, ethnicity, and language; Occupation; Gender and sex; Religion; Education; Socioeconomic status; Social capital; Plus: Personal characteristics associated with discrimination; Features of relationships; and Time-dependent relationships).

RESULTS

Of 1901 unique records, 6 met the inclusion criteria. Sex and age were the only PROGRESS factors that were reported in all studies. The majority of participants were female (84.4% to 100%), and mean ages of participants ranged from 42 to 52.3 years. Place of residence, race, education, and social capital were reported in three studies. Socioeconomic status was reported in two studies, and occupation was reported in one study. Religion, features of relationships, and time-dependent relationships were not reported in any included studies.

CONCLUSION

Limited reporting of determinants of health inequities in RCTs for SLE in Canada suggests the need for reporting standards to support equity, diversity, and inclusion practices in research.

Association of patient copayment and medication adherence in systemic lupus erythematosus

OBJECTIVE

To investigate the association of medication copayment and treatment adherence to hydroxychloroquine and immunosuppressants for SLE.

METHODS

We conducted a retrospective analysis of health claims data using Optum's de-identified Clinformatics Data Mart Database. Individuals with SLE continuously enrolled for 180 days from 1 July 2010 to 31 December 2019 were included. Adherence was defined as the proportion of days covered ≥80%. Copayment for a 30-day supply of medication was dichotomised as high (≥$10) or low (<$10). We examined the association between copayment and odds of adherence in multivariable-adjusted logistic regression models, including age, sex, race or ethnicity, comorbidities, educational attainment and household income.

RESULTS

We identified 12 510 individuals (age 54.2±15.5 years; 88.2% female sex), of whom 9510 (76%) were prescribed hydroxychloroquine and 1880 (15%) prescribed hydroxychloroquine and an additional immunosuppressant (azathioprine, methotrexate or mycophenolate mofetil). Median (IQR) 30-day copayments were $8 (4-10) for hydroxychloroquine, $7 (2-10) for azathioprine, $8 (3-11) for methotrexate and $10 (5-20) for mycophenolate mofetil. High copayments were associated with OR of adherence of 0.61 (95% CI 0.55 to 0.68) for hydroxychloroquine, OR 0.44 (95% CI 0.30 to 0.66) for azathioprine and OR 0.69 (95% CI 0.49 to 0.96) for mycophenolate mofetil. For methotrexate, the association was not significant.

CONCLUSION

In a large, administrative health claims database, we identified that high copayments were associated with reduced adherence to commonly prescribed medications for SLE. Incorporating awareness of the burden of copayments and its consequences into healthcare is essential to promote optimal medication adherence.