Outcomes evaluation of the Victorian Healthy Homes Program: a staggered parallel group cluster randomised controlled trial assessing the thermal comfort and health benefits of home energy efficiency improvements

INTERVENTION: The primary objective of a household energy efficiency retrofit in the Victorian Healthy Homes Program is to minimise winter heat loss in the home and improve thermal comfort. A range of retrofit measures can increase household energy efficiency. These include improvements to: ceiling insulation, underfloor insulation, space heating or cooling, window protection, water heaters, draught sealing external door, shower water efficiency, ventilation and lighting. The energy liaison officer visiting each house will be tasked with identifying physical and behavioural aspects of the household that will enable the determination of the types of retrofit measures that would improve winter thermal comfort, i.e. repairing a broken window or door causing cool air to enter the home. A Residential (Energy) Efficiency Scorecard assessment will also be administered in each home prior to any retrofit occurring. The Scorecard provides a cost‐based metric of the energy efficiency of a home as well as actions that would improve a home’s energy efficiency. The final decision on which retrofit measures will be performed in each home will be based on: ‐ subjective (perceived) winter thermal comfort from householders where winter thermal comfort questions are asked from recruitment as well as following formal entry into the Victorian Healthy Homes Program; AND ‐ subjective assessment of the energy liaison officer of measures that can be introduced to improve winter thermal comfort; AND ‐ objective assessment of measures and recommended energy efficiency remediation actions from the Residential Efficiency Scorecard. Energy Liaison Officer’s will visit the participant’s home twice, once before winter and again after winter. During the first visit, the energy liaison officer visiting each house will be tasked with identifying physical or behavioural aspects of the household to determine the types of retrofit measures that would improve winter thermal comfort, i.e. repairing a broken window or door causing cool air to enter the home. They will also give the participant and any other participating adults in the household a survey to complete before and after winter about how they rate their health and wellbeing. The intervention period for the purposes of the study is the astronomical winter period (22 June to 21 September) in either 2018 or 2019. However, the home modifications will remain as permanent fixtures unless the householder chooses to have them removed after the study. For the self‐reported survey measures, there will be two assessments. One in the period between February‐May (before winter) and the second in October‐February (after winter). The energy liaison officer will assess the required improvements and then arrange for the work to be performed. The required improvements will vary between households but will be selected from the range of improvements available for the study and will be recorded for each household. An audit of the home improvements will be conducted by an independent auditor. The focus will therefore be on ensuring the quality and safety of the program implementation rather than fidelity per se, given there will be variation among households in the type of intervention required. CONDITION: Cardio‐vascular health General health (self‐reported) Respiratory health (Asthma/COPD) Thermal comfort in winter PRIMARY OUTCOME: Temperature within the home ‐ outcome variable specified as mean difference in temperature. ; ; Temperature will be measured in degrees Celsius by a data logger placed in the home. ; Temperature within the home – outcome variable specified as the number of days below comfort thresholds. ; ; Temperature will be measured in degrees Celsius by a data logger placed in the home. ; ; Comfort thresholds will be based on a threshold temperature that captures when a person’s comfort is impacted by cold temperatures (for example, 18 degrees is the temperature at which a day becomes a heating‐degree day in this example from the Australian Bureau of Meteorology ‐ http://www.bom.gov.au/climate/map/heating‐cooling‐degree‐days/documentation.shtml ). SECONDARY OUTCOME: Household outcome 1 – Humidity within the home (measured by a data logger) Household outcome 2 – Change in the amount of mould/mildew observed by the household. ; ; This a self‐reported outcome with four levels (i.e. no visible mould/mildew, specks of mould/mildew, moderate mould/mildew patches, extensive discoloured areas due to mould/mildew). ; Household outcome 3 – Change in the amount of damp observed by the household. ; This a self‐reported outcome with two levels (i.e. yes – damp was noticed and no – damp was not noticed). ; Household outcome 4 – Energy use by the household ; ; This will be assessed using household energy consumption and billing data held by energy retailers. This information will be collected up to 2 years before and up to 1 year after the upgrade. Household outcome 5 – Cost‐benefit analysis of the intervention ; ; This outcome will be assessed by comparing the costs of the program to the benefits associated with changes in health utilisation, quality of life, energy consumption and greenhouse gas emissions. Individual outcome 1 – Health related quality of life (SF‐36, EQ‐5D‐5L and ASCOT instruments) Individual outcome 2 – Respiratory symptoms ; ; This will be assessed using the Medical Research Council (MRC) dyspnoea scale (which is a self‐completed question asking about shortness of breath). Individual outcome 3 – Healthcare utilisation during winter (including hospitalisations, emergency department presentations, primary care visits and pharmaceuticals) ; ; Differences between mean/median counts of these variables between the intervention and control groups. ; ; These data will be sourced from administration records and will be provided by the relevant Federal and State government organisations. For example, de‐identified MBS and PBS data will be sourced from the Department of Human Services. Individual outcome 4 – Absenteeism from school/work ; ; This is a self‐reported question that asks for the number of days that household members were absent from work/school. INCLUSION CRITERIA: This research focuses on low‐income households where at least one person has need for home care support services or has an existing health condition. To be eligible for this research project, you need to be aged 18 years or more and live in Western Melbourne or the Goulburn Valley and: ‐ have any one of the Commonwealth concession cards listed below and are receiving home care support services provided through your local council or other community organisation and plan to reside in your home for 2 years or more OR ‐ have any one of the Commonwealth concession cards listed below and are part of the Victorian Government’s Health Independence Program/Complex Care Program and plan to stay in reside in your home for 2 years or more OR ‐ have any one of the Commonwealth concession cards listed below and have a chronic respiratory disease and plan to reside in your home for 2 years or more. People with the following types of Commonwealth co