02whole_Jwalters_thesis2.pdf (1.78 MB)
A mixed-methods investigation of attitudes to chronic obstructive pulmonary disease in general practice and the utility of spirometry for improving its recognition and management
thesisposted on 2023-05-26, 05:47 authored by Walters, JAE
Chronic Obstructive Pulmonary Disease (COPD) is a major cause of disability and health care utilisation in Australia. The population prevalence is estimated at around 10% but up to 80% may be unrecognised. Lack of early diagnosis reduces the opportunity for better management. Clinical practice guidelines were developed in the 1990's to improve the diagnosis and management. The recommendation in the 2003 Australian COPDX guidelines for case finding in primary care using spirometry in high-risk subjects was based on limited evidence. A preliminary qualitative-quantitative study of the attitudes of patients with (recognised) COPD and their general practitioners (GPs) to the disease and its diagnosis identified operational and behavioural barriers to earlier diagnosis, especially lack of access and expertise in spirometry among GPs. A cluster randomised crossover study was conducted over twelve months in eight practices in Southern Tasmania offering spirometry to smokers and ex-smokers aged over 35 years. The study compared a model of opportunistic spirometry provision by visiting trained nurses (TN) with usual care (UC) where practices were provided with an electronic spirometer and spirometry training. Models were evaluated quantitatively for effectiveness, acceptability and utility in increasing the diagnosis of COPD, and qualitatively through focus groups with GPs. A longitudinal cohort of smokers was recruited in TN practices to assess the effect of feedback about normal or obstructive spirometry on smoking cessation and motivation to stop smoking using the Transtheoretical Model of stages. Spirometry provision in the TN model resulted in significantly more spirometry of high quality and testing in a greater proportion of the eligible population than the UC model. Although the TN model enabled recognition of substantial numbers of individuals with previously unrecognised obstruction, this did not translate into increased doctor-recorded diagnosis of COPD. Better practice systems for follow up, support for GPs in interpretation and realistic funding of spirometry are needed to achieve better outcomes from increased spirometry in primary care. Feedback to smokers with normal lung function was not associated with backward shift in stage of change but feedback on the presence of lung damage was associated forward shift in stage of change when allowing for smoking exposure. The odds of backward shift with feedback on lung damage, was related to pre-existing perceptions about poor lung health. Although spirometry is fundamental to making a diagnosis of COPD, provision through a model in primary care that delivers a high testing rate and high quality results will not increase diagnosis in the at-risk group without an effective protocol for appropriate action on results.