Techniques for tracing past employees. An example from an asbestos factory

Our plain-English summary of Techniques for tracing past employees. An example from an asbestos factory, by M.L. Newhouse, J.M. Williams (British Journal of Preventive & Social Medicine, 1967).

The study

• Authors: M.L. Newhouse, J.M. Williams
• Journal: British Journal of Preventive & Social Medicine
• Published: 1967;21(1):35-9
• Cited by: 6 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 002727).

In plain English

This paper described how the authors traced former workers of an asbestos factory, as a first step toward a study of their mortality. It did not report on asbestos exposure or disease. Factory records covered more than 14,000 people employed since 1913. After excluding those employed under 30 days, 4,811 male and 3,551 female past employees remained. A first search by the Ministry of Pensions and National Insurance traced 3,595 of the 4,811 men (74.7 per cent in the article's table, although its text says over three-quarters) and less than 40 per cent of the women. Efforts to trace women were abandoned, because most had changed their names on marriage. This first search found 85 per cent of men first employed 1940 to 1964, 55 per cent of those starting 1925 to 1939, and 28 per cent of those starting 1913 to 1924. The National Health Service Central Register found 37 per cent of the remaining men. Electoral rolls, local health and housing records and death indexes found 234 more. The authors concluded that workers' National Insurance and National Health numbers should be recorded accurately.

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: Methods paper describing record-tracing techniques for a planned retrospective mortality study of past employees
• Who was studied: Past employees of an asbestos factory founded in 1913 whose records covered more than 14,000 people. Those employed under 30 days were excluded, leaving 4,811 males and 3,551 females. Tracing was carried through only for the males.
• Exposure: Not studied in this paper. The population was defined by employment at the asbestos factory since 1913. No fiber types or doses are reported; the authors say they hope later to study length of exposure, types of asbestos and jobs.
• Main results:
  • In the first search, the Ministry of Pensions and National Insurance traced 3,595 of the 4,811 male past employees (74.7 per cent), according to the article's table. The article's text describes this as over three-quarters.
  • The first search traced less than 40 per cent of the female past employees.
  • Further efforts to trace women workers were abandoned.
  • The first search found 85 per cent of men first employed 1940 to 1964, 55 per cent of men first employed 1925 to 1939, and 28 per cent of men who started 1913 to 1924.
  • The second search, by the National Health Service Central Register, identified 37 per cent of the men still untraced.
  • Further searches traced 234 more men: 126 through the Electoral Roll, 82 through the Executive Council, 10 of 80 men born before 1880 through the death register index, and the remaining 16 through housing authorities or local knowledge.
  • An identification was not accepted if the date of birth did not agree within 5 years.
• The authors' conclusion: The authors concluded that the study emphasizes the importance of accurately recording both the National Insurance and the National Health number in occupations where there may be long-term effects on health.
• Limitations the authors state:
  • Women employees could not be traced, because most changed their names on marriage after leaving the factory.
  • Men first employed between 1913 and 1924 were the hardest to trace.
  • The National Health Service Central Register began in September 1939 and has no record of deaths before then.
  • Emigration without notifying the Ministry, and incomplete or inaccurate factory records, prevented a higher proportion from being identified.
  • People employed for less than 30 days were not traced.

Related studies

• Mortality among employees of an Ontario factory manufacturing insulation materials from amosite asbestos — M.M. Finkelstein (1989)
• Mortality among employees of an Ontario asbestos-cement factory — M.M. Finkelstein (1984)
• Environmental history of a factory producing friction material — J.W. Skidmore, B.L. Dufficy (1983)
• Occupational and environmental medicine: moving the factory fence or hedging our bets? — P.G. Lewis (2000)
• Mortality among long-term employees of an Ontario asbestos-cement factory — M.M. Finkelstein (1983)
• Asbestosis in long-term employees of an Ontario asbestos-cement factory — M.M. Finkelstein (1982)

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