Occupational life course and lung cancer risk in men. Findings from a socio-epidemiological analysis of job-changing histories in a case-control study

Our plain-English summary of Occupational life course and lung cancer risk in men. Findings from a socio-epidemiological analysis of job-changing histories in a case-control study, by I. Jahn, U. Becker, K.H. Jöckel, et al (Social Science & Medicine, 1995).

The study

• Authors: I. Jahn, U. Becker, K.H. Jöckel, H. Pohlabeln
• Journal: Social Science & Medicine
• Published: 1995;40(7):961-75
• Cited by: 15 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Psychosocial factors in general, and the social and psychological conditions of work and occupation in particular, have attracted little attention to the epidemiological investigation into the occupational-related causes of lung cancer. There is some evidence available concerning the impact of loss events--including job losses--on cancer development. During our research presented in this article, we examined job changes and job transitions in the occupational biography of men with regard to their circumstances in terms of (in-)voluntariness both as individual events and the job-changing histories of individuals. We expected the job-changing histories of lung cancer cases to be more involuntary than those of population controls, and vice versa. Our sample contains 391 male case-control pairs. Cases are defined as newly-diagnosed men of German nationality with a histologically- or cytologically-confirmed diagnosis of primary lung cancer. Population controls were drawn randomly from the municipality records of residents and individuals matched to cases 1:1 by age and region. Occupational histories were reconstructed, and information about other classical and suspected risk factors was collected during standardized interviews by trained interviewers. We categorized the reported reasons for job changes, and classified them with respect to voluntariness on a seven-stepped rating scale from -3 'very involuntary' to +3 'very voluntary', defining relations within the empirically established categories. The job-changing histories of individuals are described by using the average score of voluntariness. We measured the degree of voluntariness for the occupational history: (1) by the rounded average score; and (2) by the quintiles of the average score. On the basis of individuals matched odds ratios (OR) estimates are derived for the score of voluntariness unadjusted and adjusted for smoking, asbestos exposure and socio-economic group by conditional logistic regression. The investigation into job-changing histories using the average score of voluntariness lead to similar results for both measuring methods for the total study group. When the rounded score was used, job-changing histories which were assessed as 'very involuntary' and 'involuntary' (score -3 and -2) showed an elevated odds ratio of adjusted 1.41 (95%-CI: 0.57; 3.48), and when they were assessed as 'moderately involuntary' (score -1) the adjusted odds ratio was 1.59 (95%-CI: 1.02; 2.48), as compared with job-changing histories assessed as neutral (score 0). When the degree of voluntariness was measured by quintiles, the first quintile (score -3- < -0.6) showed an elevated risk of adjusted OR 1.36 (95%-CI: 0.79; 2.36) as compared to the third quintile (score -0.2- < -0.1).(ABSTRACT TRUNCATED AT 400 WORDS)

In plain English

This was a case-control study from Bremen, Germany. It compared 391 men newly diagnosed with primary lung cancer with 391 men drawn from municipal resident records, matched by age and region. Cases were recruited from August 1988 to February 1991. Interviews sought the reason for each job change; classifiable reasons were recorded for nearly 80% of changes. The authors sorted the reasons into 18 categories, scored each from -3 (very involuntary) to +3 (very voluntary), and averaged the scores over each man's working life. Occupational asbestos exposure was treated as a confounder, together with smoking and vocational training. Compared with men whose histories scored neutral, men scored 'moderately involuntary' had an adjusted odds ratio of 1.59 (95% CI 1.02 to 2.48). For 'very involuntary' or 'involuntary' histories it was 1.41 (0.57 to 3.48), which was not statistically significant. The lower odds ratios for voluntary histories (0.78 and 0.58) were also not significant. The authors named recall bias as the main problem. They also noted that for 17.9% of all reported job changes no reason was recorded, because the interviewer did not ask.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Case-control study with individually matched pairs, analysed by conditional logistic regression; a midpoint analysis of an ongoing larger study
• Who was studied: 391 male case-control pairs. Cases were newly diagnosed men of German nationality with histologically or cytologically confirmed primary lung cancer, born after 1912. 348 cases were recruited in Bremen and the rest at two clinics in Frankfurt/Main, from August 1988 to February 1991. Controls were a random sample from municipal resident records (response rate 76.4%), matched 1:1 by region and age.
• Exposure: The main exposure was the voluntariness of job changes. It was based on self-reported reasons, which were sorted into 18 categories, scored from -3 'very involuntary' to +3 'very voluntary', and then averaged per man. Classifiable reasons were reported for nearly 80% of job changes. Occupational asbestos exposure was treated as a confounder, along with smoking and vocational training. It was assessed with supplementary questionnaires and a cumulative index of lifelong working hours with asbestos exposure. No fiber types are named.
• Main results:
  • Whole group: men whose job-changing histories scored 'moderately involuntary' (score -1) had an adjusted odds ratio of 1.59 (95% CI 1.02; 2.48) compared with men whose histories scored neutral (score 0).
  • Whole group: histories scored 'very involuntary' or 'involuntary' (scores -3 and -2 combined) had an adjusted odds ratio of 1.41 (95% CI 0.57; 3.48) compared with neutral histories. The authors state this was not significant.
  • Whole group: the lower odds ratios for voluntary histories were not statistically significant. The adjusted odds ratio was 0.78 for 'moderately voluntary' (score +1) and 0.58 for 'voluntary' or 'very voluntary' (scores +2 and +3).
  • Whole group, measured by quintiles of the average score: the most involuntary (first) quintile had an adjusted odds ratio of 1.36 (95% CI 0.79; 2.36) compared with the third quintile. The fifth (most voluntary) quintile had an adjusted odds ratio of 0.63 (95% CI 0.36; 1.11 in Table 6), which the authors describe as insignificant.
  • Men over 60 (213 pairs): 'moderately involuntary' histories had an adjusted odds ratio of 2.07 (95% CI 1.15; 3.72) compared with neutral histories.
  • Men who ever gave a reason in a category, compared with men who never did: odds ratios were significantly below 1 for category 13, 'the apprenticeship was concluded' (adjusted 0.48, 95% CI 0.26; 0.89 in Table 4). They were also significantly below 1 for category 15, 'expression of demands or advantages of the new job' (adjusted 0.53, 95% CI 0.36; 0.78).
  • Asbestos as a confounder (Table 2, adjusted for smoking): the lung cancer odds ratio was 1.88 (95% CI 1.11; 3.19) for men highly exposed to asbestos at work and 1.57 (95% CI 0.90; 2.74) for moderately exposed men, both compared with men not exposed. The authors describe an increased relative risk in both upper exposure groups.
• The authors' conclusion: The authors stated there is no simple explanation for the findings. In their opinion, social-epidemiological cancer research should pay more attention to questions related to occupational histories.
• Limitations the authors state:
  • Recall bias in a retrospective design, which the authors call the main problem and say they cannot solve with their data.
  • For 17.9% of all reported job-changing events, no reason was recorded because the interviewer did not ask the question.
  • For a further 3.7% of job changes, the interviewee refused to answer or the answer could not be categorized.
  • The share of missing values varied between interviewers, from about 10 to 35%.
  • Missing values were scored as neutral, which pulls average scores toward the reference group.
  • Numbers in the youngest age group were very small.
  • Psychosocial factors were not the main focus of the parent study, so interview time and the room for additional questions were limited.
  • Data on women were not sufficient for analysis.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer.

Medical terms in this study, explained in our Lexicon: Lung Cancer, Case-Control Study, Occupational History, Odds Ratio, Asbestos Exposure.

Related studies

• Utilizing residential histories to assess environmental exposure and socioeconomic status over the life course among mesothelioma patients — B. Liu, L. Niu, et al. (2023)
• Occupational risk factors for lung cancer: a case-control study in West Germany — K.H. Jöckel, W. Ahrens, et al. (1998)
• Occupational risk factors for lung cancer in women: results of a case-control study in Germany — I. Jahn, W. Ahrens, et al. (1999)
• Occupational lung cancer risk for men in Germany: results from a pooled case-control study — I. Brüske-Hohlfeld, M. Möhner, et al. (2000)
• Occupational risk factors for renal cell carcinoma: agent-specific results from a case-control study in Germany. MURC Study Group. Multicenter urothelial and renal cancer study — B. Pesch, J. Haerting, et al. (2000)
• Occupational asbestos exposure as a risk factor for laryngeal carcinoma in a population-based case-control study from Germany — H. Ramroth, W. Ahrens, et al. (2011)

Browse return to medical research.