Wagner Norbert L, Berger Jürgen, Flesch-Janys Dieter, Koch Peter, Köchel Anja, Peschke Michel, Ossenbach Trude
Department of Environmental Health Engineering, Sri Ramachandra Medical College & Research Institute 1, Ramachandra Nagar, Porur, Chennai 600 116, India.
Environ Health. 2006 Oct 4;5:27. doi: 10.1186/1476-069X-5-27.
The healthy worker effect may hide adverse health effects in hazardous jobs, especially those where physical fitness is required. Fire fighters may serve as a good example because they sometimes are severely exposed to hazardous substances while on the other hand their physical fitness and their strong health surveillance by far exceeds that of comparable persons from the general population.
To study this effect a historic cohort study was conducted to assess mortality and life expectancy of professional fire fighters of the City of Hamburg, Germany. Fire departments and trade unions questioned the validity of existing studies from outside Germany because of specific differences in the professional career. No mortality study had been conducted so far in Germany and only few in Europe. Information on all active and retired fire fighters was extracted from personnel records. To assure completeness of data the cohort was restricted to all fire fighters being active on January 1, 1950 or later. Follow up of the cohort ended on June 30th 2000. Vital status was assessed by personnel records, pension fund records and the German residence registries. Mortality of fire fighters was compared to mortality of the Hamburg and German male population by means of standardized mortality ratios. Life expectancy was calculated using life table analysis. Multivariate proportional hazard models were used to assess the effect of seniority, time from first employment, and other occupational characteristics on mortality.
The cohort consists of 4640 fire fighters accumulating 111,796 person years. Vital status could be determined for 98.2% of the cohort. By the end of follow up 1052 person were deceased. Standardized Mortality Ratio (SMR) for the total cohort was 0.79 (95% CI, 0.74-0.84) compared to Hamburg reference data and 0.78 (95% CI, 0.74-0.83) compared to National German reference data. Conditional life expectancy of a 30 year old fire fighter was 45.3 years as compared to 42.9 year of a German male in normal population. Job tasks, rank status and early retirement negatively influenced mortality. For fire fighters with comparably short duration of employment the mortality advantage diminished with longer time since first employment. SMR of persons who retired early was 1.25 (95% CI, 1.13-1.60) in reference to the general German population and the SMR of 1.71 (1.18-2.50) in the multivariate regression model.
A strong healthy worker effect was observed for the cohort, which diminished with longer time since first employment for fire fighters with shorter duration of employment, as expected. The negative effects on mortality of job tasks, rank status and in particular early retirement indicate the presence of undetermined and specific risks related to occupational hazards of fire fighters.
健康工人效应可能会掩盖危险工作中的不良健康影响，尤其是那些需要身体健康的工作。消防员可能就是一个很好的例子，因为他们有时会严重接触有害物质，而另一方面，他们的身体健康状况以及严格的健康监测远远超过普通人群中的同龄人。
为研究这种效应，进行了一项历史性队列研究，以评估德国汉堡市职业消防员的死亡率和预期寿命。消防部门和工会对德国以外现有研究的有效性提出质疑，因为职业经历存在特定差异。德国此前尚未进行过死亡率研究，欧洲也仅有少数此类研究。从人事记录中提取了所有在职和退休消防员的信息。为确保数据完整性，队列仅限于1950年1月1日或之后在职的所有消防员。队列随访于2000年6月30日结束。通过人事记录、养老基金记录和德国居民登记处评估生命状态。通过标准化死亡率比将消防员的死亡率与汉堡和德国男性人口的死亡率进行比较。使用生命表分析计算预期寿命。使用多变量比例风险模型评估工龄、首次就业时间和其他职业特征对死亡率的影响。
该队列由4640名消防员组成，累积111,796人年。可确定98.2%队列成员的生命状态。随访结束时，有1052人死亡。与汉堡参考数据相比，整个队列的标准化死亡率比（SMR）为0.79（95% CI，0.74 - 0.84），与德国国家参考数据相比为0.78（95% CI，0.74 - 0.83）。一名30岁消防员的条件预期寿命为45.3岁，而普通德国男性为42.9岁。工作任务、职级地位和提前退休对死亡率有负面影响。对于工作年限相对较短的消防员，自首次就业以来时间越长，死亡率优势越小。提前退休人员的SMR相对于德国普通人群为1.25（95% CI，1.13 - 1.60），在多变量回归模型中为1.71（1.18 - 2.50）。
该队列观察到强烈的健康工人效应，正如预期的那样，对于工作年限较短的消防员，自首次就业以来时间越长，这种效应越小。工作任务、职级地位尤其是提前退休对死亡率的负面影响表明，消防员职业危害存在未确定的特定风险。
