This article has been updated to take account of the following correction initiated and authorised by the authors. The authors apologize for these errors.
1) The following copyright statement:
“Use of the ©MMAS is protected by US copyright laws. Permission for use is required. A license agreement is available from: MMAS Research 14725 Bellevue WA” has been added to Table 1, Figure 1, Figure 2 and Supplementary Table 1.
2) Reference 28 was cited incorrectly and has been replaced by the following MMAS-8 references:
Morisky DE, Ang A, Krousel-Wood M, Ward HJ. Predictive validity of a medication adherence measure in an outpatient setting. J Clin Hypertens 2008;10:348–54.
Morisky DE, DiMatteo MR. Improving the measurement of self-reported medication nonadherence: response to authors. J Clin Epidemiol 2011;64:255–7.
3) Reference 30 was cited incorrectly and has been replaced by the following reference:
Krousel-Wood M, Islam T, Webber LS, Re RN, Morisky DE, Muntner P. New medication adherence scale versus pharmacy fill rates in seniors with hypertension. Am J Manag Care 2009;15:59–66.
4) The numbered references have been corrected in the reference list and in the article itself.