CSIRO PUBLISHING
Australian Journal of Primary Health, 2015, 21, 429–437 http://dx.doi.org/10.1071/PY14062
Research
Medication-taking behaviour in New South Wales patients with type 2 diabetes: an observational study Teerapon Dhippayom A,B and Ines Krass B,C A
Pharmaceutical Care Research Unit, Department of Pharmacy Practice, Faculty of Pharmaceutical Sciences, Naresuan University, Phitsanulok, 65000, Thailand. B Faculty of Pharmacy, The University of Sydney, Science Road, NSW 2006, Australia. C Corresponding author. Email: [email protected]
Abstract. This study aimed to (1) determine adherence to diabetes medication in type 2 diabetes (T2D) patients; (2) describe respondents’ attitudes and beliefs about medications, and barriers to adherence; and (3) to model predictors of non-adherence. Data were collected using online and postal surveys. Diabetes patients aged 18 years who were members of the Australian Diabetes Council were invited to participate. Main outcome measures were adherence to diabetes medication using 8-item Morisky Medication Adherence Score (MMAS-8) and beliefs about medication using the Beliefs about Medicines Questionnaire. A total of 543 T2D patients responded to the survey. The median (interquartile range) MMAS-8 score was 6.8 (5.0–7.0). The prevalence of adherence (MMAS-8 score 6) was 64.6%. The proportion of respondents who expressed concern about taking medications was 53.6%. Potential predictors of adherence included age (OR, 1.83; 95% CI, 1.19–2.82), concern about medication (OR, 0.91; 95% CI, 0.87–0.96), knowledge of diabetes (OR, 0.85, 95% CI, 0.73–0.99), having difficulty in paying for medication (OR, 0.51; 95% CI ,0.33–0.79), having more than one regular pharmacy (OR, 0.59; 95% CI, 0.36–0.95), and using insulin (OR, 0.49; 95% CI, 0.30–0.81). Adherence to taking diabetes medication in a sample of the Australian T2D patient population was suboptimal. An understanding of medication-taking behaviour will assist health-care professionals to deliver appropriate and effective interventions to enhance adherence and optimise diabetes control in T2D patients. Additional keywords: adherence, attitudes, factors, medication adherence. Received 4 April 2014, accepted 3 August 2014, published online 3 September 2014
Introduction Type 2 diabetes (T2D) is an escalating global epidemic that imposes a huge cost burden on health-care systems (Zhang et al. 2010). In 2011, it affected ~1.3 million people in Australia and 366 million people around the world, and this is predicted to rise to 552 million by 2030 (Whiting et al. 2011). In Australia alone, the total annual cost of diabetes in 2005 for Australians aged 30 years was A$10.6 billion (Lee et al. 2013a). The morbidity and mortality associated with T2D result from complications associated with the duration, severity of diabetes and degree of disease control. With conclusive evidence that intensive glycaemic control can reduce the risk of complications (Stratton et al. 2000), ongoing adherence to pharmacological treatment is pivotal to controlling glycaemia, preventing complications and improving patients’ health outcomes (Lau et al. 2004). International evidence suggests that adherence to medication by T2D patients is less than optimal and highly variable, ranging from 36.0% to 93.0% (Cramer 2004). Numerous factors account for this variability, including study settings; subjects; data sources; treatment regimens; and methods of measurement of adherence using either objective or subjective measures. Journal compilation La Trobe University 2015
Examples of objective measures include the use of pharmacy claims data to calculate the medication possession ratio (MPR) and Medication Event Monitor Systems (MEMS; APREX, Division of AARDEX, Union City, CA, USA) (Cramer et al. 2008). Subjective measures involve use of self-report scales such as the Morisky Medication Adherence Scale (MMAS) (Morisky et al. 2008) and Brief Medication Questionnaire (BMQ) (Svarstad et al. 1999). Attitudes to medications among diabetes patients have also been investigated overseas. A US study of 806 White and African-American diabetes patients (Piette et al. 2010) found that a large proportion of respondents expressed serious skepticism about the safety and necessity of their prescription medications. More than one-third of patients agreed that ‘most prescription medications are addictive’, 22% agreed that ‘prescription medications do more harm than good,’ and 16% agreed that ‘people who take prescription medications should stop their treatment for a while every now and again’ (Piette et al. 2010). Overall, more negative attitudes towards medication were expressed by African–American compared with White respondents. A UK study of 121 patients with T2D reported that negative beliefs that taking medication would ‘cause unpleasant www.publish.csiro.au/journals/py
430
Australian Journal of Primary Health
What is known about the topic? *
International evidence suggests that adherence to taking medication by type 2 diabetes patients is highly variable, ranging from 36.0% to 93.0%.
What does this paper add? *
Medication-taking adherence among this sample of Australians with type 2 diabetes was suboptimal and negatively influenced by concern about medications, younger age, diabetes knowledge, medication cost, having a regular pharmacy, and the use of insulin.
side effects’ and ‘lead to weight gain’ were held by 24.1% and 13.9% of respondents, respectively (Farmer et al. 2006). Moreover, lower adherence has consistently been shown to be associated with weaker perceptions of necessity of treatment, and more concerns about treatment (Horne et al. 2013). Most studies measuring adherence to medication in T2D patients have been conducted overseas and little is known about attitudes and behaviours of medication taking in the Australian T2D population. The aim of this study therefore was: (i) to determine adherence to antidiabetic therapies in the Australian primary care T2D population; (ii) to describe respondents’ knowledge, attitudes and beliefs about medications used to treat T2D, and perceived barriers to adherence; and (iii) to model predictors of non-adherence in the Australian primary care T2D population. Methods Study design and ethical approval This observational study used a cross-sectional survey design and received approval from the University of Sydney Human Research Ethics Committee.
T. Dhippayom and I. Krass
indicated, in the first page of the link, their willingness to complete a hardcopy version in preference to the online version. Two weeks after a questionnaire was mailed out, a reminder letter, another copy of the questionnaire and a reply paid envelope were posted to non-respondents. Measures Diabetes medication adherence The 8-item Morisky Medication Adherence Score (MMAS-8) (Morisky et al. 2008) was used to identify medication adherence in the present study. The total MMAS-8 score ranges from zero to eight, with higher scores indicating better adherence; scores are interpreted as follows: low adherence (score
Australian Journal of Primary Health, 2015, 21, 429–437 http://dx.doi.org/10.1071/PY14062
Research
Medication-taking behaviour in New South Wales patients with type 2 diabetes: an observational study Teerapon Dhippayom A,B and Ines Krass B,C A
Pharmaceutical Care Research Unit, Department of Pharmacy Practice, Faculty of Pharmaceutical Sciences, Naresuan University, Phitsanulok, 65000, Thailand. B Faculty of Pharmacy, The University of Sydney, Science Road, NSW 2006, Australia. C Corresponding author. Email: [email protected]
Abstract. This study aimed to (1) determine adherence to diabetes medication in type 2 diabetes (T2D) patients; (2) describe respondents’ attitudes and beliefs about medications, and barriers to adherence; and (3) to model predictors of non-adherence. Data were collected using online and postal surveys. Diabetes patients aged 18 years who were members of the Australian Diabetes Council were invited to participate. Main outcome measures were adherence to diabetes medication using 8-item Morisky Medication Adherence Score (MMAS-8) and beliefs about medication using the Beliefs about Medicines Questionnaire. A total of 543 T2D patients responded to the survey. The median (interquartile range) MMAS-8 score was 6.8 (5.0–7.0). The prevalence of adherence (MMAS-8 score 6) was 64.6%. The proportion of respondents who expressed concern about taking medications was 53.6%. Potential predictors of adherence included age (OR, 1.83; 95% CI, 1.19–2.82), concern about medication (OR, 0.91; 95% CI, 0.87–0.96), knowledge of diabetes (OR, 0.85, 95% CI, 0.73–0.99), having difficulty in paying for medication (OR, 0.51; 95% CI ,0.33–0.79), having more than one regular pharmacy (OR, 0.59; 95% CI, 0.36–0.95), and using insulin (OR, 0.49; 95% CI, 0.30–0.81). Adherence to taking diabetes medication in a sample of the Australian T2D patient population was suboptimal. An understanding of medication-taking behaviour will assist health-care professionals to deliver appropriate and effective interventions to enhance adherence and optimise diabetes control in T2D patients. Additional keywords: adherence, attitudes, factors, medication adherence. Received 4 April 2014, accepted 3 August 2014, published online 3 September 2014
Introduction Type 2 diabetes (T2D) is an escalating global epidemic that imposes a huge cost burden on health-care systems (Zhang et al. 2010). In 2011, it affected ~1.3 million people in Australia and 366 million people around the world, and this is predicted to rise to 552 million by 2030 (Whiting et al. 2011). In Australia alone, the total annual cost of diabetes in 2005 for Australians aged 30 years was A$10.6 billion (Lee et al. 2013a). The morbidity and mortality associated with T2D result from complications associated with the duration, severity of diabetes and degree of disease control. With conclusive evidence that intensive glycaemic control can reduce the risk of complications (Stratton et al. 2000), ongoing adherence to pharmacological treatment is pivotal to controlling glycaemia, preventing complications and improving patients’ health outcomes (Lau et al. 2004). International evidence suggests that adherence to medication by T2D patients is less than optimal and highly variable, ranging from 36.0% to 93.0% (Cramer 2004). Numerous factors account for this variability, including study settings; subjects; data sources; treatment regimens; and methods of measurement of adherence using either objective or subjective measures. Journal compilation La Trobe University 2015
Examples of objective measures include the use of pharmacy claims data to calculate the medication possession ratio (MPR) and Medication Event Monitor Systems (MEMS; APREX, Division of AARDEX, Union City, CA, USA) (Cramer et al. 2008). Subjective measures involve use of self-report scales such as the Morisky Medication Adherence Scale (MMAS) (Morisky et al. 2008) and Brief Medication Questionnaire (BMQ) (Svarstad et al. 1999). Attitudes to medications among diabetes patients have also been investigated overseas. A US study of 806 White and African-American diabetes patients (Piette et al. 2010) found that a large proportion of respondents expressed serious skepticism about the safety and necessity of their prescription medications. More than one-third of patients agreed that ‘most prescription medications are addictive’, 22% agreed that ‘prescription medications do more harm than good,’ and 16% agreed that ‘people who take prescription medications should stop their treatment for a while every now and again’ (Piette et al. 2010). Overall, more negative attitudes towards medication were expressed by African–American compared with White respondents. A UK study of 121 patients with T2D reported that negative beliefs that taking medication would ‘cause unpleasant www.publish.csiro.au/journals/py
430
Australian Journal of Primary Health
What is known about the topic? *
International evidence suggests that adherence to taking medication by type 2 diabetes patients is highly variable, ranging from 36.0% to 93.0%.
What does this paper add? *
Medication-taking adherence among this sample of Australians with type 2 diabetes was suboptimal and negatively influenced by concern about medications, younger age, diabetes knowledge, medication cost, having a regular pharmacy, and the use of insulin.
side effects’ and ‘lead to weight gain’ were held by 24.1% and 13.9% of respondents, respectively (Farmer et al. 2006). Moreover, lower adherence has consistently been shown to be associated with weaker perceptions of necessity of treatment, and more concerns about treatment (Horne et al. 2013). Most studies measuring adherence to medication in T2D patients have been conducted overseas and little is known about attitudes and behaviours of medication taking in the Australian T2D population. The aim of this study therefore was: (i) to determine adherence to antidiabetic therapies in the Australian primary care T2D population; (ii) to describe respondents’ knowledge, attitudes and beliefs about medications used to treat T2D, and perceived barriers to adherence; and (iii) to model predictors of non-adherence in the Australian primary care T2D population. Methods Study design and ethical approval This observational study used a cross-sectional survey design and received approval from the University of Sydney Human Research Ethics Committee.
T. Dhippayom and I. Krass
indicated, in the first page of the link, their willingness to complete a hardcopy version in preference to the online version. Two weeks after a questionnaire was mailed out, a reminder letter, another copy of the questionnaire and a reply paid envelope were posted to non-respondents. Measures Diabetes medication adherence The 8-item Morisky Medication Adherence Score (MMAS-8) (Morisky et al. 2008) was used to identify medication adherence in the present study. The total MMAS-8 score ranges from zero to eight, with higher scores indicating better adherence; scores are interpreted as follows: low adherence (score
