Biomedical subjects

Helle Soll-Johanning

Publications and source records attributed to Helle Soll-Johanning.

4 recordsLinked to original sources

PubMed2004

Occupational exposure to air pollution and cancer risk among Danish urban mail carriers.

OBJECTIVES: Our objective was to study the risk of cancer associated with exposure to air pollution among mail carriers. METHODS: We carried out a retrospective cohort study of 17,233 persons who had been mail carriers during the period 1898-1996. Data on employment was obtained from company files. Data on cancer was obtained from the Danish Cancer Registry. RESULTS: Male mail carriers employed for more than 3 months had a low incidence of cancer, standardised incidence ratio (SIR) 0.92. For cancers related to air pollution the risk estimates were 0.96 for lung cancer, 0.91 for laryngeal cancer and 0.98 for bladder cancer. A significant low risk for cancer of the oesophagus (SIR 0.50), kidney (SIR 0.73), prostate (SIR 0.81) and skin (melanoma) (SIR 0.87) was seen. Among female mail carriers the risk pattern showed a significant excess of cancer of the cervix uteri (SIR 2.24). CONCLUSION: In our study of mail carriers who had spent most of their day doing physical hard work outside in the general air pollution we saw no excess in cancers related to air pollution compared with the general population of Copenhagen. This might be due to the protective effect of physical activity.

Aged↗

PubMed2004

Referral bias in hospital register studies of geographical and industrial differences in health.

INTRODUCTION: The Danish National Hospital Register contains four patient types: full-time inpatients, part-time inpatients, outpatients and emergency ward patients. The aim of the present study was to investigate whether results from comparative hospital register studies depend on which patient types we choose to include in the analysis. METHODOLOGY: The hospital register was linked to the centralised civil register and the employment classification module. All economically active persons in Denmark aged 20-59 years 1st January 1995 (N = 2,281,480) were followed for six years. We calculated SIRs, first by county then by industry and finally by industry adjusted for county, for a variety of diagnostic groups and for each of the following types of cases: A) full-time inpatients, B) all inpatients, C) all inpatients and outpatients, D) all patients. The ratio between the maximum and the minimum of the four types of SIRs was calculated for each combination of the examined population groups and diseases. A max/min ratio was regarded as a sign of referral bias if it was above 1.2 and statistically significant. RESULTS: When calculating SIRs by county 46.7 percent of the max/min ratios signified referral bias. The percentage was 5.5 when calculating SIRs by industry and only 1.7 when they were calculated by industry adjusted for county. CONCLUSIONS: Estimates of geographical health differences are often distorted by differences in the health care organisation. Estimates of industrial health differences tend to be robust with a few identifiable exceptions. Standardisation for county will eliminate bias.

Adult↗

PubMed2003

Lung and bladder cancer among Danish urban bus drivers and tramway employees: a nested case-control study.

BACKGROUND: The combustion of fossil fuels produces small amounts of mutagenic and carcinogenic compounds. We investigated the association between employment and lung and bladder cancer in Danish bus drivers and tramway employees. METHODS: We carried out a nested case-control study of 153 lung and 84 bladder cancer cases, and 606 controls sampled in a cohort of 18 174 bus drivers or tramway employees employed in Copenhagen during the period 1900-1994. The cases and controls or their next of kin were interviewed about smoking, along with occupational and residential history. An exposure index based on which bus routes the bus drivers had mainly been driving was established. Relative risks (RRs) were estimated by conditional logistic regression. RESULTS: The analysis showed decreasing risk for lung cancer with increasing years of employment as a bus driver (RR = 0.97 for each added year, 95% confidence interval = 0.96-0.99). The air pollution index based on main bus for the bus drivers showed no positive correlation with risk.

Adult↗

PubMed2002

A validation of information on occupation--data from a nested case-control study.

OBJECTIVES: To evaluate the validity of information about employment obtained from self-respondents and proxies in a nested case-control study. METHODS: We interviewed 230 self-respondents and 652 proxies covering 237 cancer cases and 645 controls. Questions about employment as a bus driver, other jobs, and residence were asked. Golden standard was employment data obtained from personnel records. RESULTS: All categories of respondents tended to over-report the length of employment, and respondents aged above 70 years had significantly decreased odds ratio for disagreement between interview and company files compared with respondents below the age of 60 years. There were no significant differences in whether the respondent was a case or control as there were no differences in whether the respondent was a self-respondent or a proxy. The validity of the reported employment time was statistically independent of the interval between death and proxy contact. Compared with the self-responders, the proxies reported significantly fewer jobs and residential areas. CONCLUSIONS: In general, data obtained from cases and controls not knowing that the study was about cancer and without the interviewer's knowing who were cases and who were controls appeared good. The quality of information obtained from proxies appeared good as well. There seems to be no problem in interviewing very old people about a specific job when they are mentally prepared for it. The time interval between death and proxy contact was without importance.

Adult↗