TY - JOUR
T1 - The correlation between 4 adherence measurements methods in patients with rheumatoid arthritis using methotrexate
AU - Hebing, Renske C F
AU - Elhendy, Nada
AU - van Geel, Eva H
AU - van Heuckelum, Milou
AU - Nurmohamed, Michael T
AU - van den Bemt, Bart J F
N1 - © 2023 British Pharmacological Society.
PY - 2023/12/4
Y1 - 2023/12/4
N2 - AIMS: Methotrexate (MTX) is the cornerstone in the treatment of rheumatoid arthritis (RA) patients. However, adherence to MTX therapy is not optimal, and instruments to assess medication nonadherence are warranted. To date there is no consensus on the best method to determine adherence to MTX. The aim of this study was to assess the correlation between adherence assessed with a Medication Event Monitoring System (MEMS) vs. pill count, MTX-polyglutamate (PG) concentration and Compliance Questionnaire-Rheumatology (CQR) in patients with established RA. Second, the correlations between these methods and the Disease Activity Scores of 28 joints (DAS28) were examined.METHODS: Adult RA patients currently treated with MTX were included. Multivariable linear and logistic regression were used, with adherence assessed with MEMS as dependent variable vs. pill count, MTX-PG concentrations, CQR as independent variables and DAS28 vs. each of the 4 adherence measurements. Covariates were included, such as comedication, age and use of corticosteroids.RESULTS: In total, 190 consecutive RA patients were included. Pill count was correlated with adherence assessed with MEMS (linear regression, β = 0.588, 95% confidence interval = 0.255-0.921, P < .001), whereas CQR and MTX-PGs were not. Logistic regression confirmed the correlation between dichotomized adherence and pill count only (β = 4.47, 95% confidence interval = 1.31-7.64, P = .006). No other correlations were found, either for all adherence outcomes or DAS28.CONCLUSION: Measuring adherence with MEMS is correlated with pill count, whereas other methods were not correlated with MEMS or with DAS28. Pill count can be used to estimate adherence to MTX therapy, in case MEMS is not achievable.
AB - AIMS: Methotrexate (MTX) is the cornerstone in the treatment of rheumatoid arthritis (RA) patients. However, adherence to MTX therapy is not optimal, and instruments to assess medication nonadherence are warranted. To date there is no consensus on the best method to determine adherence to MTX. The aim of this study was to assess the correlation between adherence assessed with a Medication Event Monitoring System (MEMS) vs. pill count, MTX-polyglutamate (PG) concentration and Compliance Questionnaire-Rheumatology (CQR) in patients with established RA. Second, the correlations between these methods and the Disease Activity Scores of 28 joints (DAS28) were examined.METHODS: Adult RA patients currently treated with MTX were included. Multivariable linear and logistic regression were used, with adherence assessed with MEMS as dependent variable vs. pill count, MTX-PG concentrations, CQR as independent variables and DAS28 vs. each of the 4 adherence measurements. Covariates were included, such as comedication, age and use of corticosteroids.RESULTS: In total, 190 consecutive RA patients were included. Pill count was correlated with adherence assessed with MEMS (linear regression, β = 0.588, 95% confidence interval = 0.255-0.921, P < .001), whereas CQR and MTX-PGs were not. Logistic regression confirmed the correlation between dichotomized adherence and pill count only (β = 4.47, 95% confidence interval = 1.31-7.64, P = .006). No other correlations were found, either for all adherence outcomes or DAS28.CONCLUSION: Measuring adherence with MEMS is correlated with pill count, whereas other methods were not correlated with MEMS or with DAS28. Pill count can be used to estimate adherence to MTX therapy, in case MEMS is not achievable.
KW - DMARDs
KW - behaviour
KW - outcome measurements
KW - pharmacology
KW - rheumatoid arthritis
UR - http://www.scopus.com/inward/record.url?scp=85180179015&partnerID=8YFLogxK
U2 - https://doi.org/10.1111/bcp.15980
DO - https://doi.org/10.1111/bcp.15980
M3 - Article
C2 - 38048762
SN - 0306-5251
JO - British journal of clinical pharmacology
JF - British journal of clinical pharmacology
ER -