Pulmonary Disorders: COPD

Evaluation of COPD Effect on Ability to Perform Essential Law Enforcement Job Functions

COPD is associated with decreased oxygen delivery from both loss of air exchange tissue due to alveolar changes and decreased capability of air exchange due to bronchial constriction. Severity of impairment in performing physical activities from the changes associated with COPD can vary among persons with similar profiles in terms of symptoms, smoking history and spirometry.

Functional capacity testing protocols validated for clinical use in COPD patients such as the 6 minute walk test, the Glittre Activities of Daily Living Test and others involve a low level of exertion, being designed for patients with quite significant impairment, thus making them not applicable for assessing LEOs with milder disease.12 No functional capacity test designed for COPD patients has been validated in LEOs.

Ability to exert to a specified level for a specified time is dependent on several factors, of which pulmonary air exchange, the component of primary concern in COPD, is only one. Inability to perform essential physically demanding job functions or functional testing elements may be due to other disorders affecting muscle function or to inadequate general fitness.

Job Task Simulation Testing
Throughout the recommendations above in this document Job Task Simulation Testing (JTST) was recommended for evaluation of LEOs regarding any adverse effect of COPD on the ability to perform. This recommendation was made for two reasons: no studies have been performed to correlate any surrogate testing or fitness testing with ability to safely and effectively perform the essential duties of a law enforcement officer in a particular agency; and essential tasks may vary significantly from one agency to another.

The Southeastern Pennsylvania Transportation Authority (SEPTA) requires all officers, male and female, to be able to complete a 1.5 mile run in 12 minutes, intended demonstrate an aerobic capacity of 42.5 mL/kg/min. This requirement is based on a study of essential job functions in this specific agency. SEPTA’s standard has withstood legal challenge.16

Many law enforcement training establishments, whether academies or in-service training facilities, have the ability to place individuals in simulations of various job tasks. A physician consulting with a police department may need to work closely with the department’s training division in order to craft a multi-faceted set of simulations that would assess any adverse effect of COPD on performance.

Surrogate Testing for Adverse Effect of COPD
If it is not possible to use a test incorporating essential job function activities, surrogate testing to a level consistent with the maximum aerobic demand likely to be encountered performing essential job functions may be necessary. No literature has been identified reporting direct assessment of the oxygen consumption or of physiological workload of law enforcement officers performing essential job functions while on-duty. Correlations have been made to published listings of energy expenditure, measured in metabolic equivalents (METs), for other tasks that are similar to components of essential law enforcement job functions.17 The activity-MET list offered by Jetté was generated by expert opinion and a collection of information from members of a panel whose agenda was disability assessment. This activity listing of MET equivalents has been maintained and expanded slowly with increasing numbers of activity-associated MET levels being measured directly.18 Although this list does not offer direct evaluation of incumbent LEOs performing physical LEO tasks, it does offer a number of activities that are likely representative of functions performed by LEOs. Many of these activities have been assigned MET ratings in the range of 12 METs.

Job descriptions for LEOs have also been developed and made public by at least two agencies, most notably Massachusetts Human Resources Division and California Police Officers Standards and Training (POST) Commission.19,20 Chapter 3 of this ACOEM guidance for LEOs delineates a set of essential job functions that was developed in conjunction with law enforcement organizations and officers as subject matter experts.

One small study has measured energy expenditure during simulation of a foot chase and apprehension of a resisting person as a part of designing an occupation-specific cardiac rehabilitation program (see Table 5).21 The peak METs were 14.0 (±2.2) with the mean working MET level was 10.5 (±3.2). However, although subjects were fitted with facemasks to measure oxygen consumption, VO2 data were not presented. But, using the standard conversion factor of 3.5 ml O2/kg/min for METS to VO2, these values translate to a maximum oxygen consumption of 49 ml O2/kg/min and an average consumption of 35 ml O2/kg/min. Adams also did not report times for completing the tasks. The components of this simulation as presented in Table 5 might serve as a guide for developing an essential-job-function-based physical activity challenge test.

Table 5. LEO Job Function Simulations for Energy Expenditure

In a live field operation, the actual energy expenditures are likely to be higher than those attributed to surrogate tasks based on the presumption of higher degrees of activity and the added physiological demand from psychological factors. For a variety of reasons, a police physician may be confronted with needing to request a functional evaluation with no possibility of performing it as a set of job function simulations. Treadmill exercise testing performed using a ramp protocol to maximum effort will supply limited information regarding maximum attainable MET capacity. Ramp protocols use more continuous increase in speed and incline over a set time period, usually 6-12 minutes, as opposed to the standard Bruce protocol which advances effort in steps. Ramp protocols, thus, might be more consistent with actual police responses. The police physician should discuss the particulars of the testing with the medical director of the testing facility since ramp protocols are not standardized. If such testing is used, the ACOEM LEO Task Group recommends that achievement of a MET equivalence of 12 be used as an acceptable value for allowing the LEO to be cleared to full duty.

Whether evaluation is performed using job task simulation or surrogate testing, it is not the role of the police physician to make the determination of whether failure is due to a medical condition or to inadequate conditioning. This is particularly so in the case of applicants. In performing a fitness-for-duty evaluation of incumbents, however, the police physician may need to address this issue with recommendation that the LEO undergo formal cardiopulmonary exercise testing (CPET or CPX) to more precisely define whether the inability to successfully perform job tasks simulation testing is based on pulmonary or other disease versus “fitness.” Formal CPET/CPX involves monitoring oxygen consumption during exercise testing to directly measure VO2.