The Authors Reply: We appreciate Drs Samo's and Bogucki's interest in our efforts to systematically study several issues related to fitness for duty determination in firefighters. We also welcome the opportunity to respond to the questions they have raised and to discuss further some of the NFPA 1582 medical requirements.
We agree that the essential job functions (EJFs) of hazardous materials response overlap but are not synonymous with those of firefighting. The members of our study cohort, however, were all also municipal firefighters in addition to their hazardous materials duty with the state. Therefore, as currently active firefighters, they were an appropriate study population for a simulated application of various NFPA 1582 and other proposed medical requirements to the results of their medical examinations.
Drs Samo and Bogucki go on to emphasize the difference between Category A and Category B conditions as we had done ourselves on page 930 of our article. We acknowledged on page 930 that the final 1997 version of NFPA 1582 would not automatically disqualify all those who fail the numerical hearing requirements. We pointed out the 1997 NFPA 1582 made hearing requirements Category B conditions and specified additional language about functional testing (job-specific hearing test). Therefore, our results support the idea that the 1997 version of the standard is more practical.
Notwithstanding the move of hearing requirements to Category B, the lack of scientific evidence to determine the minimum hearing requirements of firefighting and hazardous materials duty and the lack of validated "job-specific hearing tests" still leave hearing standards a contentious and controversial issue. We are in complete agreement with Drs. Samo and Bogucki that further research is required to address this difficult question. In fact, this was one of the major conclusions of our study.
With regard to resting blood pressure, NFPA 1582 states under Category B that "Acceptable hypertension is a blood pressure less than 180/100 and no target organ damage." This would seem to imply that pressures exceeding this standard would render a firefighter "unfit" based on the "severity or degree" of the hypertension. We are in complete agreement that mild to moderate hypertension should not disqualify a firefighter. We found 10% of our cohort to have blood pressure elevations (>140/90 mm Hg). Only 2%, however, had elevations in blood pressure of ≥180/100 mm Hg. Disqualification of such individuals until treatment lowers blood pressure to acceptable levels is prudent in our opinion. Therefore, we feel that the NFPA 1582 numerical guideline for resting blood pressure is quite reasonable.
Drs Samo and Bogucki also questioned the basis for spirometry criteria. They point out that the NFPA and the Occupational Safety and Health Association do not advocate minimum pulmonary function requirements. The NFPA does, however, recommend that spirometry be done as part of such examinations. Therefore, we wanted to examine the utility of spirometry and determine how many firefighters had values below arbitrary cutoffs. While 6% had either a forced vital capacity or a 1-second forced expiratory volume of less than 80% predicted, very few were lower than 70% predicted and none were below 60% predicted. Therefore, in this study, in which none of the subjects had more than apparently mild degrees of lung disease, spirometry seemed to play little role in individual fitness for duty evaluations.
Emerging evidence, however, may show a link between spirometry and "fitness" in firefighters. In companion studies of the same cohort (S.N. Kales, MD, MPH, et al, unpublished data), we found that failing various (non-pulmonary function-based) medical requirements, increasing morbidity scores, and obesity were all associated with lower pulmonary function on average. Another recent study1 found the forced vital capacity to be a predictor of poor aerobic capacity in firefighters. As further information becomes available, spirometry might be utilized as one of several tests that may identify firefighters who should undergo additional testing.
We agree with Drs Samo and Bogucki that the validity of the minifitness evaluation is questionable, and we discussed this in our article. As we explained in our discussion, this is one of the reasons why we eliminated its use from subsequent examinations. We also agree that it is problematic to mix medical requirements with the assessment of physical standards. It should be acknowledged, however, that many firefighters do not undergo any periodic medical or physical requirements testing, and many become progressively less fit over the years. This is obviously another contentious area and one that will require more research to determine how medical programs and physical fitness standards programs might identify those who can no longer safely perform the physically demanding EJFs of firefighting.
We regret that Table 4 was transposed during the conversion of our accepted manuscript to the galley proofs and we failed to catch this error. The original correct Table 4 is included here for the readers' benefit. Table
We disagree with the assertion that "a large disparity of understanding" existed among our examining physicians regarding medical standards and firefighting EJFs. The attending physicians' fitness determinations were based on their own judgment and not on any preset medical requirements. The differential failure rates among attending physicians are most likely accounted for by the physicians' different tolerances for allowing firefighters to continue active duty with various medical abnormalities and their different degrees of reluctance for failing firefighters. Such lack of consistency led to our conclusion that the uniform application of objective medical requirements is needed to determine fitness for duty in a more consistent and fair manner. As a result of our study, we subsequently introduced minimum standards for resting blood pressure, vision, and hearing.
Finally, we agree with Drs Samo and Bogucki that more research is needed to answer fitness for duty questions. While examining EJFs is important, we feel that a prospective study of firefighting cohorts to determine the risk factors for injury, incapacitation, and other adverse outcomes will provide the most valuable evidence.
Stephen N. Kales, MD, MPH
Department of Medicine; Harvard Medical School; Department of Occupational Medicine; Harvard School of Public Health; Boston, MA
David C. Christiani, MD, MPH, MS
Departments of Occupational; Medicine and Epidemiology; Harvard School of Public Health; Department of Medicine; Harvard Medical School; Boston, MA
1. Hegmann KT, Tavris DR. Firefighters' fitness for duty: a study of the predictors for poor aerobic capacity. J Occup Environ Med.
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