Statistical and econometric approaches to evaluating large-scale public health interventions

Nick Preval — PhD candidate 2010- ongoing

Supervisors:Michael Keall,
Arthur Grimes (Waitato University),
Philippa Howden-Chapman

Abstract:Public policy is increasingly guided by cost benefit analyses and cost effectiveness analyses, and there is an increasing requirement for large scale public projects to be systematically evaluated. For example, in 2007 New Zealand adopted the Gateway Process, a system of systematic reviews undertaken at key stages in a large scale projects’ lifecycle.
Large scale public health interventions are no exception. My PhD thesis explores the evaluation of one such intervention, the Warm Up New Zealand: Heat Smart (WUNZ:HS) programme.

WUNZ:HS is a $340 million project with a goal of retrofitting 188,000 homes with improved insulation and heating over four years which began in 2009. Insulation and heating retrofits have become major targets of government investment both internationally and in New Zealand and the WUNZ:HS programme is expected to produce multiple co-benefits, including health, energy efficiency and job creation.

Working as part of a team contracted to evaluate WUNZ:HS I have gained access to data and experience in carrying out various analyses. The large number of participant homes (29,745) means that the evaluation presented an opportunity to evaluate changes in rare events such as respiratory hospitalisation, which smaller RCTs carried out by the Healthy Housing Team have not been able to address due to power issues.

Distinct from work done by others as part of the official evaluation (recently completed), my PhD will include the following:

• Expanding and clarifying the analysis of pharmaceutical costs that I carried out after developing a protocol with Rachel Foster.
• Exploring sub-analyses of health data including by rental type and ethnicity.
• Obtaining an additional year of health data for participants and controls, thus raising the study power and enabling analysis of multi-year trends.
• Combining temperature, energy usage and hospitalisation costs in various models in order to refine the results from separate analyses.
• Refining my modelling of mortality costs
• Carrying out a policy comparison between the WUNZ:HS programme and Australia’s failed Home Insulation Programme.