Taking The Occupational History

DIAGNOSIS AND TREATMENTTaking the Occupational HistoryTHE OCCUPATIONAL AND ENVIRONMENTAL HEALTH COMMITTEE* OF THE AMERICAN LUNGASSOCIATION OF SAN DIEGO AND IMPERIAL COUNTIES; San Diego, CaliforniaThe occupational history is an integral part of a thoroughmedical interview, but may be difficult to interpret. Aconvenient format for obtaining an individual occupationalhistory data base is provided, with guides to theinterpretation of pertinent responses. Once conipleted,the occupational history can be extended by selectedfollow-up questions and by consulting authoritativeinformation sources available to the clinician. Theoccupational history can be used on four levels: basic(a knowledge of the patient's current occupation andimplications of the present illness for employment),diagnostic (to investigate an association with the presentillness), screening (for individual surveillarice), andcomprehensive (to investigate complex problems indepth, usually in consultation with other occupationalhealth professionals). The format provided is suitable forthe screening level and to initiate investigation at thediagnostic and comprehensive levels.clinician places great emphasis onthe patient's medical history. The well-known directionof Osier to "listen to the patient" is accepted withoutquestion by virtually all physicians. Yet many clinicianswho would never omit the family history from a thorough interview, or disregard the patient's current medication in the evaluation of a new and unexplained rash, willignore or disregard that part of the patient's history dealing with one third of the patient's life. Often, mention ofthe patient's current occupation will be omitted entirelyfrom the medical record or will be confined to billinginformation (1).The occupational history is an integral part of a thorough medical history, but its proper application requiresa fund of knowledge and training (1, 2). In this way, theoccupational history is no different from the family history or the past medical history. Without a working knowledge of occupational medicine, however, the occupational history is a bewildering catalogue of exposures to unfamiliar chemicals and the physical or psychological stresses of many jobs. The complexity of interpreting the occupational history is discouraging to many clinicians whomight otherwise incorporate it into their practice.In 1978, the American Lung Association of San Diegoand Imperial Counties devised an occupational historyform that was extensively used in metropolitan San Diego and elsewhere. In the second phase of this continuingproject, the Association's Committee on Occupationaland Environmental Health has adapted the form for conT H E CONSCIENTIOUS*Tee Lamont Guidotti, M.D., M.P.H., Chairman; Jan H. Cortez, B.S., Staff.Members of the Occupational History Subcommittee: Herrold L. Abraham,M.D.; William Hughson, M.D., Ph.D.; Abraham D. Krems, M.D., Ph.D.; Thomas S. Neuman, M.D.; Andrew L. Bryson, M.S.; and Brian I. Heramb, B.S. From the American Lung Association of San Diego and Imperial Counties; SanDiego, California.Annals of Internal Medicine. 1983;99:641-651.venient insertion in the medical record. (This forrri isreproduced full size on pages 643-644 for convenience inxerographic copying.) We discuss here the purpose, forniat, and use of the occupational history.Reasons for Obtaining the Occupational HistoryA frequent objection to the occupational history is thatit is an impractical addition to an already extensive database on each patient and is unnecessary in the evaluationof most patients. However, when properly used, the occupational history need not be burdensome. Like every other component of a thorough patient interview, it may beabbreviated, expanded, or specifically focused, but itshould never be omitted.Although the performance of an occupational historyrequires some cost in time and effort, the benefits can beextraordinarily high. Such a payoff cannot be expected inevery case, of course, but over time the value of inquiryinto occupation becomes apparent as cases are identifiedin which a significant exposure, ergonomic problem, orsafety hazard would otherwise have been overlooked. Ifthe performance of virtually risk-free investigative procerdure is beneficial to many patients, the additional effort toimplement it merits the consideration of a conscientiousclinician.Legal precedent is currently incomplete. However, theliability of the physician should be cause for concern if acorrectable occupational hazard is ignored or if a potentially compensable disability is inadequately evaluatedand falsely denied or falsely certified (3).This is an era when health care financing is dominatedby employer payment of premiums for third-party cover-;age and workers' compensation. There is a distinct trendtoward contractual arrangements between health care financing agents and health care providers to provide carefor groups of patients. The adequacy of a provider's management of occupational illness and injury will, likelyemerge as a factor to be considered in view of the uncontrolled rise in costs to the employer of employee healthinsurance and workers' compensation assessments, aswell as collective bargaining agreements.Although occupational medicine has recently receivedmuch more attention in the medical literature, it is not apassing interest. Rather, concern about occupational illnesses and injuries historically runs in cycles in the United States; this concern reached a'irecent nadir in the1960s from which it is now regaining prominence. In Europe, the appreciation of occupational associations of illness and injury has been more consistent than in theUnited States (1). 1983 American College of Physicians641

Four Levels of Use of the Occupational HistoryAs in all medical data-gathering activities, the occupational history must be used selectively (4, 5), A comprehensive evaluation is simply not necessary for most patients seen in a primary care setting. However, a generalawareness of the patient's occupation, or lack of employment, is almost always desirable for the proper management of adults. Four levels of use of the occupationalhistory can be identified,BASICThis basic level is the one appropriate for most primary care problems, in which the presenting illness isacute, presents no diagnostic dilemma, and is straightforward to manage. The only essential datum is the patient'scurrent occupation or employment status (if unemployedor retired). The implications ofthe occupational historyare threefold: Is there a direct occupational associationthat may be overlooked that bears on the patient's condition and alters management, such as a welder whose"simple" diagnosis of influenza may really be metal fumefever? Is there an occupational association that is reportable, such as a simple back strain that the patient on questioning recalls having occurred while on the job? Whatare the implications for the patient's return to work, suchas laryngitis that affects a teacher, who may have to delaya return to the classroom?DIAGNOSTICA more complex medical problem may require a limited series of questions designed to identify a specific occupational association, without necessarily reviewing thepatient's entire occupational history. An example is a patient with an entrapment syndrome (usually carpal turinel) who on questioning is shown to have an ergonomicbasis for the condition, such as repetitive rotation at thewrist on an assembly line. Here, the same questions pertain as in the basic level, but the occupational historyassists in the diagnosis and manipulation of the patient'sjob assignment or work practices. Examples of the latterinclude preventing a patient with an allergy from sustaining further exposure to the offending agent in the workplace, or teaching a patient with chronic low back painthe correct technique for lifting objects,SCREENINGA more complete occupational history is needed whenaccumulating a data base for screening patients or groupsof patients. This may be in the context of surveillance, inwhich a patient at risk for a condition is followed forearly detection of that condition; or periodic healthscreening, in which persons in generally good health arefollowed for disease prevention or early detection of common illnesses (6). An example of the former may be aworkei- in a foundry, smelter, battery plant, or drop-hanimer operation who is at risk for lead intoxicatiori. Anexample of the latter may be the executive who, beforeentering management, put himself through college byworking summers on construction projects where asbestos was used. In this situation, the history should high542light significant exposures, provide an adequate data baseto modify the screening procedure if necessary, and allowreconstruction of the most probable attribution of liability if the patient subsequently develops an occupationallyrelated condition. It should be noted that this documentation protects employers against liability for problemsthat were more plausibly associated with exposure onprevious jobs and assists the employee in making claiinsin the future by providing a less biased record of pastexposure. The occupational history form is designed to beused for this purpose.COMPREHENSIVEThe most complete occupational history is appropriatefor the investigation of complex medical problems indepth. At this level, the history must be comprehensiveand detailed, and explore all reasonable alternative riskfactors. Such a comprehensive ievaluation is obviously impractical for most situations and almost always requiresconsultation with specially-trained occupational healthprofessionals. Examples of difficult cases requiring thisapproach include interstitial pneunionitis, pneumoconioses, peripheral neuropathies, bladder cancer, leukemia,recurrent fever of unknown origin, and others involvingevery organ system. Occasionally, such investigationslead eventually to the identification of newly recognizedoccupational illnesses, as in the case of vinyl chloride-associated hepatic angiosarcoma, dimethyl-aminoproprionitrile-associated autonomic dysfunction, dibromochloropropane-associated infertility, and silicosis-induced immunosuppression resulting in acinetobacter pneumonia.Difficult cases such as these require an evaluation far beyond the scope of the occupational history form providedhere, but the investigation may properly begin with thisinstrument.Structure and Purpose of the Occupational History FormThe occupational history form is divided into threeparts. The occupational profile is an inventory of occupational experience from which exposure to hazards andthe degree of risk can be reconstructed. The occupationalexposure inventory is a directed interview intended toidentify factors of susceptibility, to alert the clinician to ahistory of occupationally related disorders, and to confirm and extend the history of hazardous exposures. Theenvironmental history is intended to alert the physicianto the possibility of home or avocational exposures,which are not strictly occupational but may produce asimilar outconie. All three parts are essential to the proper use of the occupational history form and must be reviewed together for adequate evaluation. The form is designed for convenient self-administration; it can be completed while the patient is waiting or mailed tp the patientbefore a scheduled appointment. Because it is self-administered, the form can be used in situations where no suitably trained staff person is available to conduct an interview.The occupational profile is a comprehensive inventoryof the patient's occupations, employers, and potential exposures. This part of the occupational history form isNovember 1983 Annals of Internal Medicine Votume 99 Number 5