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Validation of the Sinhala version of the Morisky Medication Adherence Scale to determine medication adherence in patients with bipolar affective disorder on lithium therapy

Uthpali Mannapperuma, Priyadarshani Galappatthy, Varuni A de Silva, Raveen Hanwella, Raveendra Laal Jayakody, Donald E Morisky


Rationale, aims and objectives: The Morisky Medication Adherence Scale (MMAS-8) is a self-reported scale used in assessing medication adherence in patients on chronic therapy. Medication adherence is a neglected area of research in Sri Lanka and in this study we have attempted to validate the Sinhala translation of the MMAS-8 to determine medication adherence among patients stabilized on lithium therapy for bipolar disorder (BD).

Methods: The MMAS-8 was translated to Sinhala with standard forward and backward translations from English to Sinhala. Patients with BD on stable doses of lithium were administered the Sinhala version of the MMAS-8. During the same visit, the serum lithium concentration was measured. Criterion validity was assessed using therapeutic serum lithium concentrations as the gold standard. Internal consistency was assessed using Cronbach’s alpha and Spearman’s rank correlation was used to assess test-retest reliability.

Results: From a sample of 240 patients, 82.1% were considered adherent, with serum lithium concentration >0.4 mmol/L. The mean MMAS-8 score was 6.95±1.3. According to the MMAS-8 scale, 13.3% reported low adherence while 43.3% reported medium and high adherence equally using MMAS cut offs <6, 6 to<8 and 8 respectively. The scale sensitivity to identify adherence at a cut-off score of 6 was 86.3%. The test–retest reliability value was 0.708 (p<0.001). Internal consistency was found with a Cronbach’s alpha value of 0.608 for the 8 items of the scale.

Conclusion: The Sinhala version of MMAS-8 can be used as a sensitive instrument to identify medication adherence in patients with bipolar disorders.


Bipolar affective disorder, Eight-item Morisky Medication Adherence Scale, medication adherence, MMAS-8, person-centered healthcare, serum lithium, Sinhala version, validation

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Leclerc, E., Mansur, R.B. & Brietzke, E. (2013). Determinants of adherence to treatment in bipolar disorder: A comprehensive review. Journal of Affective Disorders 149 (1-3) 247-252.

Gonzalez-Pinto, A., Mosquera, F., Alonso, M., López, P., Ramirez, F., Vieta, E. & Baldessarini, R.J. (2006). Suicidal risk in bipolar I disorder patients and adherence to long-term lithium treatment. Bipolar Disorders 8 (5 Pt 2) 618-624.

Sajatovic, M., Levin, J.B., Sams, J., Cassidy, K.A., Akaqi, K., Aebi, M.E., Ramirez, L.F., Safren, S.A. & Tatsouka, C. (2015). Symptom severity, self-reported adherence, and electronic pill monitoring in poorly adherent patients with bipolar disorder. Bipolar Disorders 17 (6) 653-661.

Schaffer, A., Isometsä, E.T., Tondo, L. et al. International Society for Bipolar Disorders Task Force on Suicide: meta-analyses and meta-regression of correlates of suicide attempts and suicide deaths in bipolar disorder. Bipolar Disorders 17 (1) 1-16.

Verdoux, H., Lengronne, J., Liraud, F., Gonzales, B., Assens, F., Abalan, F. & van Os, J. (2000). Medication adherence in psychosis: predictors and impact on outcome. A 2-year follow-up of first-admitted subjects. Acta Psychiatrica Scandinavica 102 (3) 203-210.

Brunton, L., Lazo, J. & Parker, K. (2005). Goodman and Gilman's The Pharmacological Basis of Therapeutics, 11th edn. New York, NY: McGraw-Hill Medical.

Ng, F., Mammen, O.K., Wilting, I., Sachs, G.S., Ferrier, I.N., Cassidy, F., Beaulieu, S., Yatham, L.N., Berk, M. & International Society for Bipolar Disorders. (2009). The International Society for Bipolar Disorders (ISBD) consensus guidelines for the safety monitoring of bipolar disorder treatments. Bipolar Disorders 11 (6) 559-595.

Morisky, D.E., Ang, A., Krousel‐Wood, M. & Ward, H.J. (2008). Predictive validity of a medication adherence measure in an outpatient setting. Journal of Clinical Hypertension 10 (5) 348-354.

Morisky, D.E., Green, L.W. & Levine, D.M. (1986). Concurrent and Predictive Validity of a Self-reported Measure of Medication Adherence. Medical Care 24 (1) 67-74.

Morisky, D.E. & DiMatteo, M.R. (2011). Improving the measurement of self-reported medication nonadherence: Final response. Journal of Clinical Epidemiology 64, 258-263.

Krousel-Wood, M.A., Islam, T., Webber, L.S., Re, R.S., Morisky, D.E. & Muntner, P. (2009). New Medication Adherence Scale Versus Pharmacy Fill Rates in Seniors with Hypertension. American Journal of Managed Care 15 (1) 59-66.

de Oliveira-Filho, A.D., Morisky, D.E., Neves, S.J.F., Costa, F.A. & de Lyra Jr, D.P. (2014). The 8-item Morisky Medication Adherence Scale: Validation of a Brazilian–Portuguese version in hypertensive adults. Research in Social & Administrative Pharmacy 10 (3) 554-561.

Al-Qazaz, H.K., Hassali, M.A., Shafie, A.A., Sulaiman, S.A., Sundram, S. & Morisky, D.E. (2010). The eight-item Morisky Medication Adherence Scale MMAS: Translation and validation of the Malaysian version. Diabetes Research and Clinical Practice 90 (2) 216-221.

De las Cuevas, C. & Peñate, W. (2015). Psychometric properties of the eight-item Morisky Medication Adherence Scale (MMAS-8) in a psychiatric outpatient setting. International Journal of Clinical Health Psychology 15 (2) 121-129.

Plakas, S., Mastrogiannis, D., Mantzorou, M., Adamakidou, T., Fouka, G., Bouziou, A., Tsiou, C. & Morisky, D.E. (2016). Validation of the 8-Item Morisky Medication Adherence Scale in Chronically Ill Ambulatory Patients in Rural Greece. Open Journal of Nursing 6 (3) 158.

Lee, W-Y., Ahn, J., Kim, J-H., Hong, S.K., Kim, Y.T., Lee, S.H. & Morisky, D.E. (2013). Reliability and validity of a self-reported measure of medication adherence in patients with type 2 diabetes mellitus in Korea. Journal of International Medical Research 41 (4) 1098-1110.

Montes, J.M., Maurino, J., de Dios, C. & Medina, E. (2013). Suboptimal treatment adherence in bipolar disorder: impact on clinical outcomes and functioning. Patient Preference and Adherence 7, 89-94.

Ibrahim, A.W., Yahya, S., Pindar, S.K., Wakil, M.A., Garkuwa, A. & Sale, S. (2015). Prevalence and predictors of sub-optimal medication adherence among patients with severe mental illnesses in a tertiary psychiatric facility in Maiduguri, North-eastern Nigeria. Pan African Medical Journal 21, 39 doi:10.11604/pamj.

Hou, R., Cleak, V. & Peveler, R. (2010). Do treatment and illness beliefs influence adherence to medication in patients with bipolar affective disorder? A preliminary cross-sectional study. European Psychiatry 25 (4) 216-219.

Central Bank of Sri Lanka. (2014). Economic and Social Statistics of Sri Lanka. Colombo: Central Bank of Sri Lanka.

Hulley, S.B., Cummings, S.R., Browner, W.S., Grady, D.G. & Newman, T.B. (2007). Designing Clinical Reserch. 3rd edn. Philadelphia: Lippincott Williams and Wilkins.

Loewenthal, K.M. (2001). An Introduction to Psychological Tests and Scales. 2nd edn. London: Psychology Press.

Streiner, D.L., Norman, G.R. & Cairney, J. (2014). Health measurement scales: a practical guide to their development and use. New York: Oxford University Press.

Nagarkar, A.M., Gadhave, S.A., Sharma, I., Choure, A. & Morisky, D. (2013). Factors influencing medication adherence among hypertensive patients in a tertiary care hospital, Pune, Maharashtra. National Journal of Community Medicine 4 (4) 559-563.

Korb‐Savoldelli, V., Gillaizeau, F., Pouchot, J., Lenain, E., Postel-Vinay, N., Plouin, P.F., Durieux, P. & Sabatier, B. (2012). Validation of a French Version of the 8‐Item Morisky Medication Adherence Scale in Hypertensive Adults. Journal of Clinical Hypertension 14 (7) 429-434.

Althubaiti, A. (2016). Information bias in health research: definition, pitfalls, and adjustment methods. Journal of Multidisciplinary Healthcare 9, 211-217.



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