An evaluation of the quality of evidence underpinning diabetes management models: a review of the literature

Objective There is a paucity of research on the quality of evidence relating to primary care workforce models. Thus, the aim of the present study was to evaluate the quality of evidence on diabetes primary care workforce models in Australia.

Methods The National Health and Medical Research Council of Australia's (National Health and Medical Reseach Council; 2000, 2001) frameworks for evaluating scientific evidence and economic evaluations were used to assess the quality of studies involving primary care workforce models for diabetes care involving Australian adults. A search of medical databases (MEDLINE, AMED, RURAL, Australian Indigenous HealthInfoNet and The Cochrane Institute), journals for diabetes care (Diabetes Research and Clinical Practice, Diabetes Care, Diabetic Medicine, Population Health Management, Rural and Remote Health, Australian Journal of Primary Health, PLoS Medicine, Medical Journal of Australia, BMC Health Services Research, BMC Public Health, BMC Family Practice) and Commonwealth and state government health websites was undertaken to acquire Australian studies of diabetes workforce models published 2005-13. Various diabetes workforce models were examined, including 'one-stop shops', pharmacy care, Aboriginal services and telephone-delivered interventions. The quality of evidence was evaluated against several criteria, including relevance and replication, strength of evidence, effect size, transferability and representativeness, and value for money.

Results Of the14 studies found, four were randomised controlled trials and one was a systematic review (i.e. Level II and I (best) evidence). Only three provided a replicable protocol or detailed intervention delivery. Eleven lacked a theoretical framework. Twelve reported significant improvements in clinical (patient) outcomes, commonly HbA1c, cholesterol and blood pressure; only four reported changes in short- and long-term outcomes (e.g. quality of life). Most studies used a small or targeted population. Only two studies assessed both benefits and costs of their intervention compared with usual care and cost effectiveness.

Conclusions More rigorous studies of diabetes workforce models are needed to determine whether these interventions improve patient outcomes and, if they do, represent value for money.

What is known about the topic? Although health systems with strong primary care orientations have been associated with enhanced access, equity and population health, the primary care workforce is facing several challenges. These include a mal-distribution of resources (supply side) and health outcomes (demand side), inconsistent support for teamwork care models, and a lack of enhanced clinical inter-professional education and/or training opportunities. These challenges are exacerbated by an ageing health workforce and general population, as well as a population that has increased prevalence of chronic conditions and multi-morbidity. Although several policy directions have been advocated to address these challenges, there is a lack of high-quality evidence about which primary care workforce models are best (and which models represent better value for money than current practice) and what the health effects are for patients.

What are the implications for practitioners? Although there has been an increase in the number of primary care workforce models implemented in Australia, there is a need for more rigorous research to assess whether these interventions are effective in producing improved health outcomes and represent better value for money than current practice. Researchers and policymakers need to make decisions based on high-quality evidence; it is not obvious what effect the evidence is having on primary care workforce reform.

What does this paper add? This study demonstrated several strengths and weaknesses of Australian diabetes models of care studies. In particular, only five of the 14 studies assessed were designed in a way that enabled them to achieve a Level II or I rating (and hence the 'best' level of evidence), based on the NHMRC's (2000, 2001) frameworks for assessing scientific evidence. The majority of studies risked the introduction of bias and thus may have incorrect conclusions. Only a few studies described clearly what the intervention and the comparator were and thus could be easily replicated. Only two studies included cost-effectiveness studies of their interventions compared with usual care.