Lifestyle

SmokingPrintable version


LASA154

Contact: Marjolein Visser

Background
Smoking is an important lifestyle variable that negatively influences health and physical functioning of older persons. In addition, smoking status often changes in old age as the consequence of incident disease.

Table 1: smoking assessed in the LASA study

Year:

LASA Wave:

1992/93

B

1995/96

C

1998/99

D

2001/02

E

2002/03

2B

2005/06

F

2008/09

G

Questions on:

Current smoking

X

X

X

X

0

X0

X0

Past smoking

X

X

X

X

0

X0

X0

Age start smoking

X

X

X

X

0

X0

X0

Age stop smoking

X

X

X

X

0

X0

X0

Current cigarette or shag smoking

X*

X

X*

X

0

X0

X0

Number of cigarettes or shags a week

X*

X

X*

X

0

X0

X0

Current cigar or pipe smoking

X**

X**

X**

X

0

X0

X0

Number of cigars or pipes a week

X**

X**

X**

X

0

X0

X0

Past cigarette or shag smoking

- - -

X

0

X0

X0

Number of cigarettes or shags (past) a week

- - -

X

0

X0

X0

X = available for the first cohort (age 55 – 85 years at baseline in 1992/93)
0 = available for the second cohort (age 55 – 65 years at baseline in 2002/03)
* Cigarette and shag smoking were assessed separately in 1992-93 and 1998-99
** Cigar and pipe smoking were assessed separately in 1992-93, 1995-96 and 1998-99 and the number of packets (50 g) of pipe tobacco was assessed per month and not per week.

Measurements in LASA
In LASA, both current smoking status (never, former, current smoker) and smoking history (age when started smoking, age when stopped smoking) were assessed at each examination during the medical interview. In addition, for current smokers quantitative information was obtained for the following products: cigarettes, shag, cigars and pipes.

At the LASA E examination (2001/2002) two slight adjustments to the smoking questionnaire were made. First, for current smokers the number of smoked cigarettes or shag per week was combined into one question. The same was done for the number of smoked cigars / pipes. Secondly, to allow the calculation of pack-years of smoking, former smokers were asked the average number of cigarettes or shag they smoked per week (or per day).

Previous use in LASA
Smoking status: Many papers used current smoking status as a covariate or determinant in the statistical analyses (1). Most often, respondents were classified into three (never, former, current) or two categories (never/former, current). The following smoking variable was also used to indicate current smoking status: never, former, pipe/cigar, cigarette/shag (2).

Quantitative information: To investigate a potential dose-response relationship among current smokers, heavy smokers (> 20 cigarettes/day) were contrasted with those smoking less than 20 cigarettes per day (2). Similarly, the number of years since smoking cessation was used to categorize former smokers (2).

Smoking history: Smoking status at age 25 years, 40 years, and at the age during the LASA B examination can also be assessed using a different approach. At each age, smoking status (never, former, current) was assessed based on the age of the respondent when smoking was started and stopped. A former smoker who stopped smoking at least 15 years ago was categorized as a never smoker. The rationale for this was that mortality among former smokers approaches the level of never smokers after a smoking cessation time of 10 to 20 years (3-6). As a cumulative measure of smoking exposure, the number of years smoked can be calculated for every age (7).

Pack-years
The calculation of pack-years is another way to indicate smoking history. Pack-years is the average number of packs of cigarettes smoked per day times the number of years smoking. It is always assumed that one pack contains 20 cigarettes. All non-smokers are set to 0 by definition. Only starting at the LASA E examination, former smokers are being asked to report the average number of cigarettes smoked, allowing the calculation of pack-years for former smokers.

References

  1. Pluijm SM. Visser M, Smit JH, Popp-Snijders C, Roos JC, Lips P. Determinants of bone mineral density in older men and women: body composition as mediator. J Bone Miner Res 2001;16:2142-51.
  2. Visser M, Launer LJ, Deurenberg P, Deeg DJH. Past and current smoking in relation to body fat distribution in older men and women. J Gerontol A Biol Sci Med Sci 1999;54:M293-8.
  3. Kawachi I et al. Smoking cessation in relation to total mortality rates in women. Ann Intern Med 1993;119:992-1000.
  4. Paganini-Hill A, Hsu G. Smoking and mortality among residents of California retirement community. Am J Public Health 1994;84:992-5.
  5. Van Domburg et al. Smoking cessation reduces mortality after coronary artery bypass surgery: a 20-year follow-up study. J Am Coll Cardiol 2000;36:878-83.
  6. Wannamethee S et al. Smoking as a modifiable risk factor for type 2 diabetes in middle-aged men. Diabetes Care 2001;24:1590-5.
  7. Pluijm SM et al. A healthy lifestyle at young and old age: relationship with functional decline. In preparation.