TY - JOUR
T1 - Nonadherence to disease modifying antirheumatic drugs in the first year after diagnosis: comparing three adherence measures in early arthritis patients
AU - Pasma, Annelieke
AU - den Boer, Ethan
AU - van't Spijker, Adriaan
AU - Timman, Reininer
AU - van den Bemt, Bart
AU - Busschbach, Jan J. V.
AU - Hazes, Johanna M. W.
PY - 2016/10
Y1 - 2016/10
N2 - The aim of this study was to compare three measurement methods for non-adherence to DMARDs in early arthritis patients: the Compliance Questionnaire Rheumatology (CQR), the intracellular uptake of MTX in the form of MTX-polyglutamates (MTX-PGs) and electronic measurement with Medication Event Monitoring Systems (MEMS).DMARD na?ve early arthritis patients were included in an ongoing cohort study. MEMS were used to measure adherence continuously, while every 3 months MTX-PGs were collected together with the CQR. The associations between the measures were estimated with Spearman rank correlations. Sensitivity and specificity of the CQR against a MEMS cut-off was compared at 3, 6, 9 and 12 months. The same applied to MTX-PGs against a MEMS cut-off and MTX-PGs against a CQR cut-off. For the association between MEMS, the CQR and MTX-PGs, a multilevel linear regression model was performed with age, gender, weeks of treatment and MTX dosage as covariates.We included 206 patients. Non-adherence measured with MEMS varied over time and between DMARDs. The CQR score was not associated with MEMS non-adherence at 3, 9 and 12 months. At 9 months, MTX-PGs was associated with MEMS non-adherence, as well as with the CQR. All correlations were below 0.30.Associations between the three measures are weak. Explanations are individual differences in the uptake of MTX, and little variance in adherence between patients. Moreover, the measurement domains differ: perceptions (CQR), behaviour (MEMS) and pharmacokinetics (MTX).? The Author 2016. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
AB - The aim of this study was to compare three measurement methods for non-adherence to DMARDs in early arthritis patients: the Compliance Questionnaire Rheumatology (CQR), the intracellular uptake of MTX in the form of MTX-polyglutamates (MTX-PGs) and electronic measurement with Medication Event Monitoring Systems (MEMS).DMARD na?ve early arthritis patients were included in an ongoing cohort study. MEMS were used to measure adherence continuously, while every 3 months MTX-PGs were collected together with the CQR. The associations between the measures were estimated with Spearman rank correlations. Sensitivity and specificity of the CQR against a MEMS cut-off was compared at 3, 6, 9 and 12 months. The same applied to MTX-PGs against a MEMS cut-off and MTX-PGs against a CQR cut-off. For the association between MEMS, the CQR and MTX-PGs, a multilevel linear regression model was performed with age, gender, weeks of treatment and MTX dosage as covariates.We included 206 patients. Non-adherence measured with MEMS varied over time and between DMARDs. The CQR score was not associated with MEMS non-adherence at 3, 9 and 12 months. At 9 months, MTX-PGs was associated with MEMS non-adherence, as well as with the CQR. All correlations were below 0.30.Associations between the three measures are weak. Explanations are individual differences in the uptake of MTX, and little variance in adherence between patients. Moreover, the measurement domains differ: perceptions (CQR), behaviour (MEMS) and pharmacokinetics (MTX).? The Author 2016. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
KW - non-adherence
KW - DMARDs
KW - early arthritis
U2 - 10.1093/rheumatology/kew247
DO - 10.1093/rheumatology/kew247
M3 - Article
C2 - 27354686
SN - 1462-0324
VL - 55
SP - 1812
EP - 1819
JO - Rheumatology
JF - Rheumatology
IS - 10
ER -