Smoking and SF-36 health functioning

Abstract

Objective.

To examine the association between smoking and general health as measured by the Short-Form Health Survey (SF-36) questionnaire.

Methods.

Data derived are from three cross-sectional surveys conducted in 2000, 2001 and 2002. Respondents to the postal surveys were middle-aged employees of the City of Helsinki (1799 men and 7171 women, response rate 67%). Smoking status was divided into current heavy and moderate smokers, ex-smokers and never smokers. Health status was measured by the eight SF-36 subscales and the physical and mental component summaries.

Results.

On the physical subscales, current smokers reported poorer health than non-smokers on general health and physical functioning in men. On the mental subscales, current smokers had consistently poorer health than non-smokers. However, often only heavy smokers differed from non-smokers. No differences were found between ex-smokers and never smokers on any subscale or the component summaries of the SF-36.

Conclusions.

Differences between smoking categories were found on some physical and all mental subscales of the SF-36. The differences were slightly larger among men. As heavy smokers more often report limitations with daily activities as well as loss of well-being, these impairments potentially provide valuable incentives for non-smoking to be used in health education messages and interventions.

Introduction

The discussion on health effects of smoking has been dominated by the well-known association of smoking with several chronic diseases and subsequent mortality (World Health Organization, 2002, Ezzati and Lopez, 2004). The chronic diseases that smoking is largely responsible for include cardiovascular diseases, lung and other cancers and diseases of the respiratory system. It has been estimated that smokers may lose even up to 10 years of life because of their smoking (Anon, 2002, Doll et al., 2004, Brønnum-Hansen and Juel, 2001). However, smokers are also expected to have shorter lifetime in good health and spend more years with disability than non-smokers (Brønnum-Hansen and Juel, 2001, Nusselder et al., 2000). Yet, relatively little is known about how smoking affects general health, including functioning and personal well-being. The possible effect of smoking on self-evaluated general health is important for estimating the total health burden of smoking. Functional status and well-being are increasingly important outcome measures in medical care (Guyatt et al., 1993).

The Short-Form Health Survey (SF-36) is one of the most widely used measures of general health. The SF-36 is a broad-spectrum profile measure that consists of eight subscales and component summaries on physical and mental health. The measure basically indicates the self-assessed impact of ill-health and diseases on functioning and well-being. The primary focus is on functioning and the ability to perform daily tasks and activities. Furthermore, the SF-36 measures how people feel physically and emotionally and what they think about their health. As a non-specific measure, the SF-36 has been used in connection with various risk factors, such as hypertension (Bardage and Isacson, 2001) or obesity (Doll et al., 2000, Laaksonen et al., in press).

Only few population studies have examined the association between smoking and the SF-36. Furthermore, the results vary greatly. Some studies have found current smokers to report consistently poorer health than non-smokers or ex-smokers (Tillmann and Silcock, 1997, Wilson et al., 1999), while others have found such differences only on some SF-36 subscales (Bellido-Casado et al., 2004, Lyons et al., 1994, Mulder et al., 2001, Olufade et al., 1999). Some studies have found a dose–response relationship between the amount of smoking and one or more subscales (Mulder et al., 2001, Wilson et al., 1999). Most studies are based on very small samples (Bellido-Casado et al., 2004, Lyons et al., 1994, Olufade et al., 1999, Tillmann and Silcock, 1997), and none has examined men and women separately.

The aim of this study was to compare general health as measured by the SF-36 questionnaire between current heavy and moderate smokers, ex-smokers and never smokers among middle-aged employed men and women.