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The Scottish Executive Central Heating Programme: Assessing Impacts on Health



This report sets out the findings obtained from an evaluation of the health impacts of the Scottish Executive Central Heating Programme ( CHP). The CHP is an initiative funded by the Scottish Executive which, during the period studied (November 2002 to March 2006), provided free central heating and associated thermal efficiency measures (such as loft insulation) to:

  • homes in the public rented sector which lacked central heating; and
  • homes in the private sector which lacked central heating (or had a central heating system which was broken beyond repair), and where the householder (or her / his partner) was aged 60 or over.

The evaluation compared the experiences of a group of 1,281 households which received heating under the Programme with those of a 'comparison' group of 1,084 households not included in the CHP. A total of 67 individual outcome measures, classified into 11 discrete conceptual areas, was considered. The conceptual areas are listed, and the outcomes within each area defined, in Sections B.2 to B.12 in Appendix B. The outcomes included both direct indicators of health ( e.g. the experience of specific conditions such as high blood pressure) and a range of other indicators plausibly linked with human health ( e.g. the presence of mould or dampness in the home).

The key message from the evaluation is that the CHP significantly reduced condensation, damp and cold in recipients' homes. Recipients heated more rooms in their homes, and for longer. The Programme significantly reduced important risk factors for cardio-respiratory disease. However, there was little evidence of a clear and systematic direct impact of the Programme on health outcomes and use of health services.

The main findings of the study are summarised below.

Perceptions of warmth in the home: Three measures reflecting the ability of the dwelling's heating to provide sufficient warmth were examined; all three showed a significant effect of the CHP. It was found that, relative to households not enrolled in the CHP ('comparison' households), recipients of heating under the Programme were (i) more likely to report always being kept adequately warm in cold weather (odds ratio: 3.50 2 [95% confidence interval: 2.85 to 4.29]) 3; (ii) less likely to experience a serious problem relating to inadequate heating (odds ratio: 0.48 [95% confidence interval: 0.29 to 0.81]); and (iii) more likely to be 'very satisfied' or 'fairly satisfied' with their heating (odds ratio: 4.96 [95% confidence interval: 3.87 to 6.37]).

Patterns of heating in the home: Ten measures relating to the extent and duration of heating use were assessed. All of these exhibited significant associations with the CHP. Recipients of heating under the Programme were found to be (i) less likely to keep more than half of the rooms in the home unheated during cold weather (odds ratio: 0.22 [95% confidence interval: 0.16 to 0.29]); (ii) less likely to heat more than half of the dwelling's rooms for nine hours per day or less (odds ratio: 0.79 [95% confidence interval: 0.68 to 0.91]); and (iii) more likely to heat more than half of the home's rooms continually i.e. 24 hours per day (odds ratio: 1.28 [95% confidence interval: 1.04 to 1.58]). It was also found that in recipient dwellings the kitchen, bathroom, hall, main bedroom and second bedroom were heated for longer in cold weather than in non-recipient homes (five individual outcomes). The estimated difference in heating duration for these five room types ranged from 1.11 hours per day (for the kitchen [95% confidence interval: 0.51 hours to 1.71 hours]) to 2.37 hours per day (for the bathroom [95% confidence interval: 1.74 hours to 3.00 hours]). The average duration of heating (across all rooms in the home) was also greater for CHP recipients, the estimated difference being 1.12 hours per day ([95% confidence interval: 0.60 hours to 1.64 hours]). While all of these findings indicate a greater extent or duration of heating use, it was also found that recipients heated the main living room for a shorter period of time (estimated at 1.15 hours per day ([95% confidence interval: 0.60 hours to 1.70 hours]) than households in the comparison group.

The home environment: Nine individual outcome measures were considered in this area, all of which were found to exhibit statistically significant effects associated with receiving heating under the Programme. Recipients were found to be less likely to report the presence of environmental problems (mould, condensation and / or dampness) in any of six general room types considered (kitchen, bathroom, main living room, hall, main bedroom, second bedroom - six individual outcomes). Odds ratios for the presence of problems in these six room types ranged from 0.44 (for the second bedroom [95% confidence interval: 0.34 to 0.57]) to 0.59 (for the main living room [95% confidence interval: 0.46 to 0.75]). Those receiving heating under the Programme also reported a reduced likelihood of (i) avoiding the use of any rooms in the home due to difficulty in heating them (odds ratio: 0.43 [95% confidence interval: 0.31 to 0.59]); (ii) experiencing serious difficulty in daily life related to environmental problems (odds ratio: 0.52 [95% confidence interval: 0.31 to 0.86]); and (iii) being unable to use one or more rooms due to problems of damp or condensation (odds ratio: 0.39 [95% confidence interval: 0.15 to 1.00]).

The evaluation found limited evidence of direct impacts on health in two areas:

Specific symptoms and health conditions, and use of primary and secondary health services: A total of 21 individual outcomes was investigated in this area. Of these, 17 related to the respondent's experience of specific symptoms and health conditions. Analysis of these 17 outcomes indicated that heating recipients were less likely to report having received a first diagnosis of (i) heart disease (odds ratio: 0.69 [95% confidence interval: 0.52 to 0.91]), and (ii) high blood pressure (odds ratio: 0.77 [95% confidence interval: 0.61 to 0.97]) during the two-year period between the initial and final interviews 4. However, those receiving heating also reported an increased likelihood of receiving a first diagnosis of nasal allergy during the same period (odds ratio: 1.52 [95% confidence interval: 1.05 to 2.20]). The remaining 14 symptom- and health-related measures (which in the main represented cardiovascular and respiratory conditions, including asthma) showed no significant effect associated with the CHP. A further four measures in this conceptual area related to respondents' use of health services. None of these exhibited a significant association with the receipt of heating under the CHP.

Self-reported health-related quality of life: This area included nine outcomes (physical functioning, social functioning, role limitations due to physical problems, role limitations due to emotional problems, mental health, energy/vitality, pain, general health perception and health change over the past year) derived from the SF-36 Health Survey, a 36 item self-administered questionnaire which measures health-related quality of life in the general population. Those who received heating under the Programme reported higher (better) scores on two of the measures examined, namely the physical functioning scale (which assesses fitness and mobility), and the general health scale (which evaluates an individual's general perception of her / his state of health). However, although values of these two measures indicated a positive effect of the CHP on health, the estimated size of the difference between recipients and non-recipients of heating was small in both cases (2.51 scale units for Physical Functioning [95% confidence interval: 0.62 units to 4.40 units], 2.57 units for General Health [95% confidence interval: 0.87 units to 4.27 units]; both scales range from zero ['least good'] to 100 ['best']). No significant effect of the Programme was found for the remaining seven measures in this area.

The evaluation also considered two further areas directly related to health:

  • Long-standing illness or disability (consisting of a single outcome measure)
  • Use of medications (two outcome measures)

None of the measures in these areas was found to exhibit a significant association with receipt of heating under the CHP.

In addition to the areas reported above, the evaluation also considered the effect of the CHP on four other areas which might plausibly be expected either to reflect or to influence human health:-

Overall satisfaction with the home: Heating recipients were found to be more likely to disagree with the perception of home as 'A place I want to get away from' (odds ratio: 1.19 [95% confidence interval: 1.03 to 1.37]). However, those receiving heating also indicated that they were less likely not to move home if they were able to do so (odds ratio: 0.83 [95% confidence interval: 0.69 to 0.99]). Three further outcomes in this area showed no significant associations with the Programme.

Social contacts: Recipients were less likely than comparison group respondents to report having dissuaded friends or relatives (i) from staying overnight (odds ratio: 0.42 [95% confidence interval: 0.26 to 0.70]), and (ii) from visiting (odds ratio: 0.40 [95% confidence interval: 0.23 to 0.70]), due to poor housing conditions such as dampness or cold. Two further measures in this area were not significantly associated with the CHP.

Financial strain: Those acquiring heating via the Programme were less likely to report any degree of inability to 'manage financially' (odds ratio: 0.77 [95% confidence interval: 0.60 to 0.99]).

Health behaviours: Two measures were investigated, representing respondents' use of alcohol and cigarettes. Neither was found to be significantly associated with the Programme.

Subgroups: A limited number of subgroup analyses was performed in order to assess whether the CHP operated differentially on specific subgroups of recipients. Differential effects were investigated for three key outcomes: respiratory health problem, general health and environmental problem in main rooms in the respondent's dwelling. In investigating differential effects, attention focussed on the possible influence of housing tenure, physical house type ( e.g. 'semi-detached'), gender and age. None of the results obtained indicates that the effect of the Programme varied substantially across subgroups for the range of outcomes examined.

Overall, the results indicate that receipt of heating under the Central Heating Programme had considerable impacts on the home environment, including on conditions such as cold, damp and mould. Long-term exposure to these adverse conditions is associated with poor health and it is possible that their reduction will bring health benefits to recipients in the longer term. However, results also showed no evidence for a clear and systematic direct effect on health. The findings indicating a reduced likelihood of diagnosis with high blood pressure or heart disease, while noteworthy, must be treated with caution. Although recipients were subsequently less likely to be diagnosed with heart disease and high blood pressure than the comparison group, this difference was not accompanied by a difference in the use of health services. A diagnosis of heart disease would place an individual into a programme of monitoring and care. We would have therefore expected to see higher rates of service use in the comparison group - reflecting their greater incidence of diagnosis. The absence of differences in service use between the recipient and comparison groups suggests that the apparent difference in incidence of diagnosis may not be reliable.

The effects of environmental conditions such as damp and cold on cardio-respiratory health occur over a relatively long time period. While a respondent may feel warmer, and their walls may dry out relatively quickly following installation of heating, changes to their physiology which may delay or even prevent a diagnosis of heart disease or high blood pressure will take longer. The two year follow-up period is unlikely to have been long enough for any clear impact on cardio-respiratory health to be seen. Furthermore, housing conditions are not the only influences on health: wider economic circumstances and behaviours ( e.g. diet and exercise) can also exert considerable impact. Health benefits of the Programme may be insignificant if the rest of the individual's life and behavioural circumstances become or remain unhealthy.

We conclude that receipt of heating under the Scottish Executive's Central Heating Programme was associated with reduction of problems with cold, damp and mould, with higher levels of heating in the home, with feeling warmer in winter, and with greater level of satisfaction with heating. It was not clearly or consistently associated with direct impacts on the cardio-respiratory health of recipients, nor with reductions in NHS service use. It is possible that these direct health impacts will become visible over a longer period of time.