Prescription medicines, over-the-counter medicines and complementary and alternative medicines use in baby boomers and older South Australians and their association with health outcomes (as assessed by health services use and quality of life)

Abstract

There is growing evidence of the increasing use of medicines in older generations; however, research undertaken to critically examine specific differences in use among baby boomers and older people is limited. Understanding the complex factors that influence medicine use by baby boomers and older people is vital due to the particular risks associated with medicines use in older generations. In addition, exploring the differences in medicines usage between these generations will help to inform research and health policy to better meet the health care needs of the ageing population. This thesis, utilising South Australian (SA) population data, examines the difference in prevalence of use of medicines and the influence of social, demographic, chronic conditions and health related factors on the likelihood of being a user of prescription medicines, over-the-counter medicines (OTC) or complementary and alternative medicines (CAM). The thesis also examines the links between medicines use and health outcomes with the evaluation of their beneficial or adverse effects assessed through comparison with quality of life (QoL), health services use and biochemical markers. Population data from the SA Health Omnibus Survey, an annual face-to-face survey of randomly selected respondents, and the North West Adelaide Health Study (NWAHS) were used. Univariable and multivariable logistic regression analyses were performed in order to investigate the relationships between medicines use and demographic characteristics (including gender, household size, income, education, area of residence, work status, marital status and country of birth). Linear regression analyses were used to determine the relationship between QoL and the independent variables. The results of the analysis show that the majority of SA baby boomers and older people take a combination of prescription medicines and CAM and a large proportion of older people take a combination of prescription medicines, OTC medicines and CAM. Unemployment was shown to be a key factor for the use of prescription medicines and polypharmacy (five or more medicines), while gender and education were important factors for the use of CAM. The use of CAM and OTC medicines could potentially increase the rate of adverse effects or drug interactions. Therefore, it is important for prescribers to take a detailed medicines history prior to prescribing medicine. QoL was shown to be lower with increased use of prescription medicines and OTC medicines. However only a weak association was found between the use of CAM and QoL. The specific type of prescription medicines found to be associated with QoL were those prescribed for blood and blood forming organs, musculoskeletal system and nervous system. Cardiovascular disease (CVD) was used as an example of a chronic condition. People with CVD and without CVD had a similar QoL but the increase use of prescription medicines, OTC medicines was associated with lower QoL. Further investigation for association of the use of medicines and QoL is warranted.