Prevalence of Rheumatoid Arthritis and Drug Dispensing Patterns Among Medicaid and Medicaid–Medicare Dually Eligible Beneficiaries in Puerto Rico

Abstract

Objective To estimate the prevalence of rheumatoid arthritis (RA) in Puerto Rico, to describe disease‐modifying antirheumatic drug (DMARD) dispensing patterns by prescriber specialty, and to illustrate the impact of RA case definition on the estimated prevalence. Methods This study estimated the prevalence of RA in Puerto Rico during 2016 among Medicaid and Medicaid–Medicare dually eligible beneficiaries of the Mi Salud health care plan, a federally funded health insurance program. DMARD dispensing and cost patterns were described and stratified by provider specialty. A sensitivity analysis was conducted to evaluate the effect of RA case definition on estimated prevalence. Results The prevalence of RA in 2016 was estimated to be 2 cases per 1,000 beneficiaries, with 3 per 1,000 beneficiaries among females, 4.5 times that of males. In total, 44% of beneficiaries received conventional synthetic DMARDs (csDMARDs) only, 32% received biologic or targeted synthetic DMARDs (b/tsDMARDs) only, and 24% received a combination of csDMARDs and b/tsDMARDs. Rheumatologists and a combination of specialties accounted for the highest median number of dispensed DMARDs, with 14 each. A sensitivity analysis revealed that when RA cases with ≥3 medical claims were restricted to having ≥1 DMARD claim, the estimated prevalence changed from 6 to 3 cases per 1,000 beneficiaries. Conclusion The prevalence of RA in Puerto Rico in this study is lower than reported in the mainland US, possibly due to more stringent criteria to define RA. DMARD dispensing and cost patterns are similar to those found in other studies. Claims algorithms that identify RA have higher validity when pharmacy data is included.

Treatment Patterns Among Patients with Rheumatoid Arthritis in Puerto Rico

“…Abatacept treatment was slightly more common in SqL and LL treatment: 17, 37, and 20% of patients received abatacept as EL, SqL, and LL therapy, respectively. This treatment distribution is similar to what has been reported previously in the wider US population, where TNFis are also the most commonly used bDMARDs for the treatment of RA [6,11].…”

“…These patients also had lower exposure to bDMARDs than those treated in fee-for-service settings. A report on the distribution of DMARDs prescribed to Medicaid and Medicaid–Medicare dual beneficiaries of a federally funded health insurance program in Puerto Rico found that 24, 16, and 7% of prescriptions for RA during 2016 were for adalimumab, etanercept, and abatacept, respectively [ 11 ]. The use of newer b/tsDMARDs such as abatacept, golimumab, tocilizumab, tofacitinib, and certolizumab accounted for approximately 28% of all b/tsDMARD prescriptions dispensed to RA patients during the study period.…”

“…Although arthritis is one of the most prevalent health conditions in Puerto Rico [8], few studies have been conducted in Puerto Rican or Hispanic populations specifically [9][10][11]. Studies in the broader US population have identified some racial and ethnic disparities, reporting higher levels of disease activity and worse functional status in Hispanic patients compared with white patients, although it is not clear why this is the case [12][13][14].…”

“…The few studies that have been performed have been small [ 9 , 10 ] or have only included particular subsets of patients (e.g. Medicaid and Medicaid–Medicare dual beneficiaries [ 11 ]), and may not be representative of the overall RA population in Puerto Rico.…”