Physical fitness of industrial firefighters

Firefighting is widely known to be one of the most physically demanding civilian occupations. A subset of this is Industrial Firefighting, which places similarly high physical demands on Industrial Firefighters. Although there are some studies on community firefighters, literature is scant on Industrial Firefighters and their physical fitness. ^ A cross-sectional study of Industrial Firefighters in Petrochemical companies in Texas was carried out in 1996–98 to assess their physical fitness and to develop a set of physical agility criteria useful in their selection and ongoing fitness for duty evaluations. ^ A physical agility criteria and a fitness scorecard was developed based on seven parameters (resting heart rate, diastolic blood pressure, aerobic capacity, muscle strength, muscle endurance, trunk flexibility and total body fat) of musculoskeletal and cardiorespiratory fitness. Each indicator received a minimum of 0 to a maximum of 20 points, based on individual performance. Therefore a minimum and maximum achievable score for the entire battery of tests was 0 and 140 respectively. Of the 111 study subjects, 5 (4.5%) were far above average, 31 (28%) above average, 46 (41.5 %) average, 29 (26%) below average and 0 (0%) far below average as deemed by the physical fitness scorecard. The mean score was 77 (±23) with a minimum and maximum score of 35 and 135 respectively. ^ Following univariate analysis an exploratory factor analysis to group variables and to assess the overall role of constituent variables in total fitness of a firefighter was developed. This was followed by a stepwise linear regression analysis using aerobic capacity as a dependent variable. ^ Finally, a graded implementation strategy was devised, such that all existing Industrial Firefighters would have an opportunity to improve or maintain their physical fitness at or above average level as deemed by the fitness scorecard. ^

THE RELATIONSHIP BETWEEN DEGREE OF BLOOD PRESSURE REDUCTION AND MORTALITY AMONG HYPERTENSIVES IN THE HYPERTENSION DETECTION AND FOLLOW-UP PROGRAM

The relationship between degree of diastolic blood pressure (DBP) reduction and mortality was examined among hypertensives, ages 30-69, in the Hypertension Detection and Follow-up Program (HDFP). The HDFP was a multi-center community-based trial, which followed 10,940 hypertensive participants for five years. One-year survival was required for inclusion in this investigation since the one-year annual visit was the first occasion where change in blood pressure could be measured on all participants. During the subsequent four years of follow-up on 10,052 participants, 568 deaths occurred. For levels of change in DBP and for categories of variables related to mortality, the crude mortality rate was calculated. Time-dependent life tables were also calculated so as to utilize available blood pressure data over time. In addition, the Cox life table regression model, extended to take into account both time-constant and time-dependent covariates, was used to examine the relationship change in blood pressure over time and mortality.^ The results of the time-dependent life table and time-dependent Cox life table regression analyses supported the existence of a quadratic function which modeled the relationship between DBP reduction and mortality, even after adjusting for other risk factors. The minimum mortality hazard ratio, based on a particular model, occurred at a DBP reduction of 22.6 mm Hg (standard error = 10.6) in the whole population and 8.5 mm Hg (standard error = 4.6) in the baseline DBP stratum 90-104. After this reduction, there was a small increase in the risk of death. There was not evidence of the quadratic function after fitting the same model using systolic blood pressure. Methodologic issues involved in studying a particular degree of blood pressure reduction were considered. The confidence interval around the change corresponding to the minimum hazard ratio was wide and the obtained blood pressure level should not be interpreted as a goal for treatment. Blood pressure reduction was attributed, not only to pharmacologic therapy, but also to regression to the mean, and to other unknown factors unrelated to treatment. Therefore, the surprising results of this study do not provide direct implications for treatment, but strongly suggest replication in other populations. ^