Background
Smoking is a well known risk factor for increased mortality. Although some smokers
may survive to older ages, they often suffer from poor health and impaired quality of
life (QoL) because of chronic diseases. The construct of health-adjusted life
expectancy (HALE) combines mortality and the subjective perception of health-related
quality of life (HRQoL) into a single index. The impact of smoking on HALE might
be useful information for encouraging smokers to quit or young people not to start
smoking. However, scarce information is available, particularly from Chinese
populations, on how smoking affects HALE.
Aims
The study aimed to determine the impact of smoking on HALE among Chinese people
aged 65 years or over in Hong Kong who had enrolled in an Elderly Health Centre
(EHC).
Methods
Data on a cohort of 66,820 people enrolled in EHCs of the Department of Health during
1998 to 2001, were used. These were supplemented by a follow-up telephone survey
of a stratified (for smoking status) sample of 2,441 from the whole EHC database,
which included more recent enrollees. Two measures of HALE were used: (1) based
on a simple measure of perceived health and (2) based on quality-adjusted life years
(QALYs) estimated. The first measure had been included in the EHC database but
current information was obtained by telephone for each year of follow-up. The second
measure was only available from the survey. Multi-state life tables and Sullivan?s
method were employed to investigate HALEs among current, ex and never smokers.
The yearly transition rates between health statuses were calculated using the existing
data on self-assessed health and supplemented by the survey data. Utility scores for
calculation of QALYs used a local estimation equation for the SF-12.
Results
Men at age 65 who had never smoked could expect to live a further 20 years and
women a further 22 years. This was around 3-5 years more than for current or
ex-smokers. Both male and female never smokers at age 65 could expect to be in a
good QoL for 16 of those future years. Those still smoking at age 65 could expect 3-4
fewer years in a good QoL. People who had quit smoking before age 65 gained about
one more year in good health compared with continuing smokers.
Conclusions
It has already been estimated that smokers of all ages lose up to about 10 years of life
due to smoking. However, the longer they survive, the lower the difference in
mortality between ever smoker and never smokers. This study shows that, for those
who were still alive at age 65 years in this cohort, smoking was still detrimental to their
survival and to their QoL, especially if they were still smoking at that age. Results for
males and females were similar. Therefore, even if a smoker does not die prematurely,
their HRQoL is still affected and a never smoker will have not only longer life but more
life years in good health than an ever smoker. Stopping smoking at an earlier age
might gain back some HRQoL. / published_or_final_version / Community Medicine / Master / Master of Philosophy
| Identifer | oai:union.ndltd.org:HKU/oai:hub.hku.hk:10722/161587 |
| Date | January 2012 |
| Creators | Cheung, Wai-ling., 張惠棱. |
| Contributors | McGhee, S, Fielding, R |
| Publisher | The University of Hong Kong (Pokfulam, Hong Kong) |
| Source Sets | Hong Kong University Theses |
| Language | English |
| Detected Language | English |
| Type | PG_Thesis |
| Source | http://hub.hku.hk/bib/B48079923 |
| Rights | The author retains all proprietary rights, (such as patent rights) and the right to use in future works., Creative Commons: Attribution 3.0 Hong Kong License |
| Relation | HKU Theses Online (HKUTO) |
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