Psychometric properties of the 8-item Morisky Medication Adherence Scale in patients taking warfarin

2012 ◽  
Vol 108 (10) ◽  
pp. 789-795 ◽  
Author(s):  
Ye Wang ◽  
Ming Kong ◽  
Yu Ko

SummaryThere is no patient-reported medication adherence measure that has been validated in Singapore. This study aimed to validate the 8-item Morisky Medication Adherence Scale (MMAS) in patients taking warfarin in Singapore. A cross-sectional survey was conducted in a convenience sample of 151 patients taking warfarin at an anticoagulation clinic in 2011. Respondents completed the MMAS in English or Chinese depending on their preference. The MMAS had a Cronbach′s alpha of 0.56 and good criterion-related validity as the scale scores were associated with warfarin refill rates (p = 0.04). Respondents with higher MMAS scores were found to have a higher percentage of International Normalised Ratios (INRs) within the therapeutic range (p = 0.01), higher adherence to diet recommendations (p = 0.02), and less perceived difficulty in taking all medications (p < 0.001); they were also more likely to take warfarin at the same time every day (p < 0.001). Confirmatory factor analysis showed that the eight items loaded onto one factor (RMSEA = 0.03). The sensitivity, specificity, positive predictive value and negative predictive value of the MMAS for identifying patients with poor INR control were 73.0%, 35.6%, 49.5% and 60.5%, respectively, using the time in the therapeutic INR range as the gold standard. This study shows that the 8-item MMAS has good validity and moderate reliability in patients taking warfarin. Future research is needed to investigate the scale′s psychometric properties in other patient populations and clinical settings.

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
A Aguiar ◽  
C Piñeiro ◽  
R Serrão ◽  
R Duarte

Abstract Background Antiretroviral therapy (ART) has the most effective treatment for people with HIV, but its effectiveness depends on the individual medication adherence. Morisky Medication Adherence Scale (MMAS-8) is one of the most widely used scales to assess patient adherence. Thus, we aimed to validate a Portuguese version of MMAS-8 and determine its psychometric properties in HIV positive patients. Methods A cross-sectional survey was conducted in Centro Hospitalar Universitário São João (Porto, northern Portugal) at the infectious diseases department. After authorization to use the scale - granted by the author - and, a standard forward-backwards procedure to translate MMAS-8 to Portuguese, the questionnaire was applied to 233 patients with HIV doing ART. Reliability was assessed using Cronbach's alpha and test-retest reliability. Three levels of adherence were considered: 0 to &lt; 6 (low), 6 to &lt; 8 (medium), 8 (high). Results In the studied sample, the mean age was 45.03 years (SD = 11.63), 80.3% men, 19.3% women and 1 transgender, and 53.8% had ≤9 years of education. The mean number of prescribed ART per patient was 1.76. The mean score for the medication adherence scale was 7.29 (SD = 6.74). For the reliability analysis, 12 patients were excluded due to missing data (n = 221). Regarding the level of adherence, 22.5% were low adhering, 71.6% medium and 5.9% high. Corrected item-total correlations showed that 1 item does not correlate very well with the overall scale and was dropped. Scale reliability analysis for the remaining 7 items revealed an overall Cronbach's alpha of 0.661. Women had a protective effect on adherence (OR = 0.31;95%CI:0.15-0.66). Number of years doing ART, age of participants, and type of residence didn't show to be correlated with adherence. Conclusions MMAS-8 is a reliable and valid measure to detect patients at risk of non-adherence. A satisfactory Cronbach's alfa (0.661) was obtained. In general, adherence to medication was medium or high. Key messages This scale can be applied nationwide in other different hospitals, as it could serve as a tool for measuring adherence to ART that can allow for better health care to the ones that are low adhering. A Portuguese version of the MMAS-8 was created for measuring adherence to ART that maintained a similar structure to the original MMAS-8 and good psychometric properties.


2016 ◽  
Vol Volume 10 ◽  
pp. 1759-1766 ◽  
Author(s):  
Beata Jankowska-Polańska ◽  
Izabelle Uchmanowicz ◽  
Anna Chudiak ◽  
Krzysztof Dudek ◽  
Donald Morisky ◽  
...  

2018 ◽  
Vol 41 (5) ◽  
pp. 508-512 ◽  
Author(s):  
Susan B. Kesmodel ◽  
Olga G. Goloubeva ◽  
Paula Y. Rosenblatt ◽  
Brian Heiss ◽  
Emily C. Bellavance ◽  
...  

2009 ◽  
Vol 43 (5) ◽  
pp. 950-957 ◽  
Author(s):  
Phantipa Sakthong ◽  
Rossamalin Chabunthom ◽  
Rungpetch Charoenvisuthiwongs

Background A self-reporting questionnaire is the most convenient and cheapest way to assess medication adherence. A new 8-item self-reported Morisky Medication Adherence Scale (MMAS) has been developed and has shown better psychometric properties than the original 4-item Morisky scale. Objective To examine the validity, including convergent known-groups and construct validity, and reliability, including internal consistency and test–retest reliability, of the MMAS in Thai patients with type 2 diabetes. Methods The data were derived from a cross-sectional study. In a convenience sample, 303 type 2 diabetic outpatients were interviewed at the General Police Hospital in Bangkok, Thailand, between January and June 2007. Face-to-face interviews included MMAS, medication adherence visual analog scale (MA-VAS), and sociodemographic data. Medical records were reviewed for clinical data such as hemoglobin A1c (A1C) levels. Results Internal consistency reliability was moderate (Cronbach's α = 0.61), whereas the test–retest reliability of the MMAS was excellent (intraclass correlation coefficient = 0.83; p < 0.001). Concerning convergent validity, the MMAS had a high correlation with the 3-item Morisky scale (r = 0.77; p < 0.01) and a medium correlation with the MA-VAS (r = 0.57; p < 0 01). Regarding known-groups validity, a significant association between MMAS and A1C levels was found (χ2 = 6.7; p < 0.05). The sensitivity, specificity, positive predictive value, and negative predictive value of the MMAS were 51%, 64%, 71%, and 43%, respectively. Our factor analysis showed that the MMAS had 3 dimensions including forgetting to take medications, stopping medications when feeling better or worse, and the complexity of the drug regimen. Conclusions The 8-item MMAS can be a tool to aid in assessing medication adherence in diabetes. The poor sensitivity can be improved by increasing the number of the response choices and the cut-off score of the scale and by using specific words in some items. A modified Thai version of the 8-item MMAS may be needed.


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