Validation of the General Medication Adherence Scale in Pakistani Patients With Rheumatoid Arthritis

Abstract

The aim was to validate the Urdu version of General Medication Adherence Scale (GMAS) in patients with rheumatoid arthritis disease. Methods: A 2-month (March-April 2019) cross-sectional study was conducted in randomly selected outpatients with rheumatoid arthritis. The sample size was calculated using item-subject ratio of 1:20. The scale was evaluated for factorial, concrete, concurrent, and known group validities. Concrete validity was established by correlating scores of EQ-5D quality of life scale and GMAS adherence score. Concurrent validity was established by correlating the GMAS adherence score with pill count. Analyses for sensitivity were also conducted. Cutoff value was determined through receiver operator curve (ROC), and test-retest method was used to analyze internal consistency and reliability. Data were analyzed through IBM SPSS, IBM AMOS, and MedCalc software. The Urdu version of EQ-5D quality of life questionnaire was used with permission from developers (#ID20884). The study was approved by an ethics committee (#NOV:15). Results: A total of 351 responses were analyzed. The response rate was 98%. Reliability was in acceptable range, i.e., Cronbach a = 0.797. Factorial validity was established by calculation of satisfactory fit indices. Correlation coefficients for concrete and concurrent validities were r = 0.687, p < 0.01 and r = 0.779, p < 0.01, respectively. Known group validity was established as significant association of adherence score with insurance and illness duration (p < 0.05) that were reported. Sensitivity of the scale was 94%. Most patients had high adherence (N = 159, 45.3%).

Translation and validation of the Arabic version of the General Medication Adherence Scale (GMAS) in Saudi patients with chronic illnesses

“…Previous studies have reported a 3-factor structure of GMAS scale in patients with chronic diseases. We confirmed the 3-factor model and calculated the fit indices ( Naqvi et al, 2018 , Naqvi et al, 2019a , Naqvi et al, 2020 ). The fit indices were in the acceptable range that indicated that the 3-factor model was fit.…”

“…Adult male and female Saudi out-patients above age of 18 years who had a confirmed diagnosis of a chronic disease, with or without co-morbidities, on long-term therapy during implementation phase of adherence, for at least a month before study, were invited to participate in the study. The implementation phase of adherence is the stage in which the patient continues to take medications from the time of the first dose until the last one ( Dowrick et al, 2005 , Vrijens et al, 2012 , Naqvi et al, 2020 ).…”

Development and validation of a questionnaire to determine medical orders non-adherence: a sequential exploratory mixed-method study

“…As expected from relevant studies [ 37 – 40 ], the results of “known group comparisons” showed that females and patients with insurance had better adherence than male patients and those who lacked insurance.…”

“…The method of known groups is a typical method for supporting construct validity and is given when a test can discriminate between a group of people known to have a specific characteristic and a group who do not have the characteristic. The instrument's total score was compared based on gender and insurance coverage [37][38][39][40].…”

Vietnamese Version of the General Medication Adherence Scale (GMAS): Translation, Adaptation, and Validation

“…Regarding the validation of the GMAS studies (two interviews four weeks apart), this figure was 0.996 (p < 0.01) or 0.861 (p < 0.01). For the validation of the GMAS in osteoarthritis patients (two interviews three weeks apart), this figure was 0.875 (p < 0.001) [12,13,22,23]. In these studies, Spearman's correlation coefficients indicate that the GMAS has good stability; even though the time between the two interviews was different, the GMAS was still at a good correlation.…”