e m = 0.6-0.4(M1/M2) para miembros cuyos extremos están impedidos de ladearse.
72 Aluminum Design Manual 2�05, PART 1-8-
The current body of knowledge on the subject suggests there would be few differences between smokers and non-smokers across most of the social context variables. To explore the extent to which this holds true across the range of levels of tobacco use, smokers were categorised as light, moderate or heavy; and non-smokers as ex-regular and never regular, and these groups were compared to the population as a whole. In general, there was a weak association between smoking behaviour and the social functioning and social support measures explored, with heavy smokers being more likely to both have experienced stressful events and have lower levels of social support.
There were differences in the pattern of the association between number of stressful life events experienced (over the lifetime and in the past six months) and smoking status. Among non-smokers, ex-smokers had a higher lifetime prevalence of stressful life events than people who had never smoked regularly (97% had experienced at least one stressful life event compared with 94% of those who never smoked). However, this is probably a reflection of the high proportion of older people among ex-smokers (described in Chapter 2), since older people will have had longer exposure to the risk of stressful life events. Heavy and moderate smokers were more likely to have had stressful experiences in their lifetime than light smokers (97% compared with 92%).
A much greater difference between smokers and non-smokers is found when recent experiences, rather than lifetime experiences, are considered. Almost a third (32%) of smokers had experienced one of the stressful life events covered in the survey in the past six months, and there was little
difference between light, moderate and heavy smokers. In comparison, less than a quarter (23%) of non-smokers, both ex-smokers and those who had never smoked, reported a stressful event in the past six months. (Table 6.1)
It might be expected that heavy smoking would be associated with some forms of increased social morbidity such as divorce, separation,
unemployment and more general social stresses.
Tables 6.2 – 6.4 consider the associations between smoking status and the individual events covered by the survey. Separation and divorce was
associated with level of smoking in both men and women. Among heavy smokers 43% had
experienced separation or divorce, compared to 30% of light smokers and 23% of non-smokers. Personal injury, illness and assault were also more frequent among women who smoke heavily; among this group almost a third (32%) had experienced injury, illness or assaults compared to a fifth (20%) of women who had never smoked, or were light or moderate smokers.
(Table 6.2 and Figure 6.1)
Lifetime experiences of unemployment and major financial problems were strongly associated with heavy smoking for men, but the association was less marked for women who smoke heavily. Around one in four (24%) men who smoked heavily had suffered a financial crisis during their lifetime, compared with about one in ten (11%) men who had never smoked. Almost a half (49%) of male heavy smokers had been made redundant or sacked compared with around a third (32%) of men who had never smoked. Ex-regular smokers were just as likely as heavy smokers to have been made
redundant or sacked at sometime in their lives; their smoking status at the time of loss of work could have been either current smoker or ex- smoker but this finding may simply reflect an association of both variables with age. (Table 6.3)
Figure 6.1 Percentage who have ever experienced separation or divorce by smoking status
Never regular Ex-regular Light Moderate Heavy
0 5 10 15 20 25 30 35 40 45 50 Percentage Smoking status
Smoking, particularly heavy smoking, was associated with increased rates of lifetime experience of violence in the home, sexual abuse, running away from home, being homeless and being expelled from school for both men and women. Among current smokers 12% had experienced violence in the home, 11% had run away from home and 8% had been homeless; the corresponding figures among non-smokers were 5%, 3% and 2%. It is hard to assess patterns over the past six months as the frequencies are low.
(Table 6.4)
Experience of being cared for outside of the family as a child was associated with smoking, particularly heavy smoking, as an adult. Heavy smokers were most likely to have spent time in an institution as a child (6% had done so) or to have been taken into local authority care up to the age of sixteen (5% had been) while those who had never smoked regularly were least likely (1% in each case).
(Table 6.5)
Heavy smokers also had the lowest levels of social support. They were most likely to perceive a severe lack of social support (12% compared to 7% of non-smokers) have a primary support group of less than four people (10% compared to 4% of non- smokers), and were least likely to have seen more than two friends in the last week (70% compared with 76% of non-smokers). (Table 6.6)
Overall these findings indicate that bad experiences in both childhood and adulthood are associated with smoking, particularly heavier smoking. The direction of effect however is more difficult to determine. Is it that people with major current life stresses are more likely to smoke heavily or is it that past experience of serious life stress predisposes the individual to heavier smoking? Jarvis et al (1999) have reported that socio-economic deprivation is associated with heavy smoking. Other psychiatric morbidity surveys of people who are homeless, in prison or in psychiatric institutions (Farrell et al, 1998) indicate very high rates of heavy smokers in these populations. These vulnerable groups are also more likely to have highly stressful lives, and lower levels of social support.