Testing the activitystat hypothesis: a randomised controlled trial protocol

Background: The activitystat hypothesis proposes that when physical activity or energy expenditure is increased or decreased in one domain, there will be a compensatory change in another domain to maintain an overall, stable level of physical activity or energy expenditure. To date, there has been no experimental study primarily designed to test the activitystat hypothesis in adults. The aim of this trial is to determine the effect of two different imposed exercise loads on total daily energy expenditure and physical activity levels. Methods. This study will be a randomised, multi-arm, parallel controlled trial. Insufficiently active adults (as determined by the Active Australia survey) aged 18-60 years old will be recruited for this study (n=146). Participants must also satisfy the Sports Medicine Australia Pre-Exercise Screening System and must weigh less than 150 kg. Participants will be randomly assigned to one of three groups using a computer-generated allocation sequence. Participants in the Moderate exercise group will receive an additional 150 minutes of moderate to vigorous physical activity per week for six weeks, and those in the Extensive exercise group will receive an additional 300 minutes of moderate to vigorous physical activity per week for six weeks. Exercise targets will be accumulated through both group and individual exercise sessions monitored by heart rate telemetry. Control participants will not be given any instructions regarding lifestyle. The primary outcome measures are activity energy expenditure (doubly labeled water) and physical activity (accelerometry). Secondary measures will include resting metabolic rate via indirect calorimetry, use of time, maximal oxygen consumption and several anthropometric and physiological measures. Outcome measures will be conducted at baseline (zero weeks), mid- and end-intervention (three and six weeks) with three (12 weeks) and six month (24 week) follow-up. All assessors will be blinded to group allocation. Discussion. This protocol has been specifically designed to test the activitystat hypothesis while taking into account the key conceptual and methodological considerations of testing a biologically regulated homeostatic feedback loop. Results of this study will be an important addition to the growing literature and debate concerning the possible existence of an activitystat. Trial registration. Australian New Zealand Clinical Trials Registry ACTRN12610000248066

Quality of chronic disease care in general practice: the development and validation of a provider interview tool

BACKGROUND: This article describes the development and psychometric evaluation of an interview instrument to assess provider-reported quality of general practice care for patients with diabetes, cardiovascular disease and asthma – the Australian General Practice Clinical Care Interview (GPCCI). METHODS: We administered the GPCCI to 28 general practitioners (family physicians) in 10 general practices. We conducted an item analysis and assessed the internal consistency of the instrument. We next assessed the quality of care recorded in the medical records of 462 of the general practitioners' patients with Type 2 diabetes, ischaemic heart disease/hypertension and/or moderate to severe asthma. This was then compared with results of the GPCCI for each general practice. RESULTS: Good internal consistency was found for the overall GPCCI (Cronbach's alpha = 0.75). As far as the separate sub-scales were concerned, diabetes had good internal consistency (0.76) but the internal consistency of the heart disease and asthma subscales was not strong (0.49 and 0.16 respectively). There was high inter-rater reliability of the adjusted scores of data extracted from patients' medical notes for each of the three conditions. Correlations of the overall GPCCI and patients' medical notes audit, combined across the three conditions and aggregated to practice level, showed that a strong relationship (r = 0.84, p = 0.003) existed between the two indices of clinical care. CONCLUSION: This study suggests that the GPCCI has good internal consistency and concurrent validity with patients' medical records in Australian general practice and warrants further evaluation of its properties, validity and utility

Burden of disease and injury in Aboriginal and Torres Strait Islander peoples: The Indigenous health gap

Background: Disparities in health status between Aboriginal and Torres Strait Islander peoples and the total Australian population have been documented in a fragmentary manner using disparate health outcome measures. Methods: We applied the burden of disease approach to national population health datasets and Indigenous-specific epidemiological studies. The main outcome measure is the Indigenous health gap, i.e. the difference between current rates of Disability-Adjusted Life Years (DALYs) by age, sex and cause for Indigenous Australians and DALY rates if the same level of mortality and disability as in the total Australian population had applied. Results: The Indigenous health gap accounted for 59% of the total burden of disease for Indigenous Australians in 2003 indicating a very large potential for health gain. Non-communicable diseases explained 70% of the health gap. Tobacco (17%), high body mass (16%), physical inactivity (12%), high blood cholesterol (7%) and alcohol (4%) were the main risk factors contributing to the health gap. While the 26% of Indigenous Australians residing in remote areas experienced a disproportionate amount of the health gap (40%) compared with non-remote areas, the majority of the health gap affects residents of non-remote areas. Discussion: Comprehensive information on the burden of disease for Indigenous Australians is essential for informed health priority setting. This assessment has identified large health gaps which translate into opportunities for large health gains. It provides the empirical base to determine a more equitable and efficient funding of Indigenous health in Australia. The methods are replicable and would benefit priority setting in other countries with great disparities in health experienced by Indigenous peoples or other disadvantaged population groups. © Published by Oxford University Press on behalf of the International Epidemiological Associatio