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THE NEW YORK CITY NURSE - EPIDEMIOLOGY PROGRAM PASCAL JAMES IMPERATO, M.D., M.P.H. & T.M. Commissioner of Health City of New York
LEWIS M. DRUSIN, M.D., M.P.H. Associate Professor of Public Health Assistant Professor of Medicine Cornell University Medical College
JOHN S. MARR, M.D., M.P.H. Director, Bureau of Preventable Diseases City of New York Department of Health
ELEANOR C. LAMBERTSEN, Ed.D. Dean Cornell University-New York Hospital School of Nursing
BARBARA TOPFF OLSTEIN, M.A., R.N. Nurse Epidemiologist Instructor Division of Continuing Education Cornell University-New York Hospital School of Nursing New York, N.Y.
T HE epidemiology services of the City of New York Department of Health were first developed in the latter half of the 19th century as part of the department's Division of Contagious Diseases. In the first half of this century a division of epidemiologic services was developed within the Bureau of Preventable Diseases and its successor, the Bureau of Infectious Disease Control. The epidemiologic activities of the City of New York Department of Health include surveillance of disease, the investigation of cases and outbreaks of specific communicable diseases, and the implementation of control measures to stop or minimize the spread of disease, which includes immunization activities and coordination with local, state, and federal agencies. Until 1975 the Department of Health staffed its epidemiology unit with Address for reprint requests: Pascal J. New York, N.Y. 10013.
Vol. 53, No. 6, July-August 1977
Imperato, M.D., Commissioner of Health, 125 Worth Street,
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AND OTHERS J. IMPERATO P. J. IMPERATO
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AND
OTHERS
physicians who were primarily clinicians. This pattern, originally established in the latter part of the 19th century, met the city's needs until the 1950s. In 1972, when the department's epidemiologic activities came under new direction, studies clearly indicated that the department's epidemiologic services were costly and less than effective. In order to make the department more responsive to the city's current needs in the control of communicable diseases, it was decided to reorganize the Division of Epidemiologic Intelligence and to replace its parttime clinicians by full-time nurse-epidemiologists. This paper describes the process and its results. THE DEVELOPMENT OF EPIDEMIOLOGIC SERVICES
Epidemiologic activities have been carried out in New York City since the 18th century. It was not until the latter part of the 19th century that the Department of Health institutionalized these activities within the administrative framework of a Division of Contagious Diseases. A principal activity of this division and its successor organizations was the accurate clinical diagnosis of reported cases of communicable disease. Reports of specific communicable diseases were not accepted on their face value, especially in the years before accurate confirmatory laboratory tests were widely available. This meant that individual patients had to be examined by skilled and experienced diagnosticians and the diagnosis of the reporting physician either upheld or rejected on clinical grounds. Control measures hinged upon the confirmatory diagnosis; for this reason the Department of Health developed a cadre of well-trained diagnostician-epidemiologists. These epidemiologists were clinical physicians with diagnostic acumen. From the 1920s through the 1950s the Department of Health was able to recruit and retain sufficient numbers of physician-epidemiologists. This was especially true during the years of the Great Depression, when the steady income of municipal employment was an inducement. After World War II the older members of the staff remained since they had a large investment in pensions. But it became increasingly difficult to recruit younger physicians because of the relatively low salaries offered by the department compared to the potential remuneration of private practice and the incomes available in private and university employment. In order to deal with the problem of recruitment, the department's Bureau of Preventable Diseases came to rely increasingly on the services Bull. N. Y. Acad. Med.
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of part-time physicians who were paid for each session. The majority of these physicians were pediatricians, internists, and general practitioners in private practice who worked an average of 2 1/2 hours per day for the Bureau of Preventable Diseases.
EPIDEMIOLOGIC SERVICES, 1965-1974 By the mid-1960s many of the full-time medical epidemiologists who had entered the Department of Health in the 1930s began to retire. The responsibility for providing epidemiologic services devolved increasingly upon the part-time epidemiologists. This was a less than satisfactory situation, since many types of outbreak require long hours of field work. Part-time staff do not have the time to conduct such investigations properly. Between 1965 and 1974 most of the serious outbreaks were managed by a small nucleus of full-time staff who often served long overtime hours without remuneration. In 1970, 31 part-time field epidemiologists were employed by the Department of Health. The Division of Epidemiology in which they worked was headed by a full-time medical epidemiologist and staffed with one full-time medical epidemiologist. In addition, the division provided experience and training to one epidemic intelligence service officer from the U.S. Public Health Service Center for Disease Control. The chief of the Division of Epidemiology reported to a full-time medical director of the Bureau of Infectious Disease Control. By 1972 the Division of Epidemiology had lost both its chief and its remaining full-time epidemiologist, thereby causing an upward shift of operational responsibility to the director of the Bureau of Infectious Disease Control. This person was also responsible for administering the Division of Tropical Medicine, which operates four clinics in the city and provides for 25,000 visits per year, the Division of Veterinary Medicine, and the Immunization Program. In spite of intensive efforts, the department was unable to attract any candidates for either the position of chief epidemiologist or the four full-time epidemiologist positions. There were several reasons for this inability to recruit. Salary levels were locked into the New York City civil service system and were about 25% less than those for comparable positions in state and national governments. Even with parity salaries it is difficult to attract professionals into New York City because of the relatively high cost of living and the high state and city income taxes. Also, Vol. 53, No. 6, July-August 1977
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OTHERS
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TABLE I. FIELD ACTIVITIES OF MEDICAL EPIDEMIOLOGISTS BY DISEASE AND BOROUGH, NEW YORK CITY, 1970
Other diseases Meningitis Salmonellosis Hepatitis Total number of cases % of total % of total % of total % of total assigned for Borough investigation Number in borough Number in borough Number in borough Number in borough
1,934
1,268 454
496 1,196 950 788 371
30% 52% 49% 62% 82%
403 517 399 143 26
24% 23% 21% 11% 6%
442 187 379 107 24
26% 8% 19% 9% 5%
344 392 206 230 33
20% 17% 11% 18% 7%
7,633
3,801
50%
1,488
19%
1,139
15%
1,205
16%
Bronx Brooklyn Manhattan Queens Richmond
1,685 2,292
Total
there are only a limited number of medical epidemiologists in the United States; the steady decline in the incidence of major communicable diseases over the past two decades has made communicable disease epidemiology increasingly unattractive to medical graduates. Thus, fewer physicians enter the field and the pool of candidates diminishes. At the same time that the department was unable to recruit full-time epidemiologists, the part-time staff began to diminish through retirement. By 1972 there were five fewer part-time epidemiologists than there had been in 1970. The department encountered the same difficulties in recruiting part-time clinicians for these positions as it had when it tried to find full-time staff. The major reasons for the department's inability to recruit part-time physicians were the noncompetitive remuneration offered and the unwillingness of physicians to carry out field investigations in many areas of the city for fear of physical injury. This was not an imaginary risk; several field epidemiologists already had been hurt on one or more occasions, sometimes by the individuals they were trying to help. FUNCTION OF MEDICAL EPIDEMIOLOGISTS, 1970
In 1970, 50% of all cases investigated by field epidemiologists in New York City were of hepatitis (Table I), 19% salmonellosis, 15% meningitis, and 16% other diseases such as trichinosis, ornithosis, and food intoxication. As shown in Table I, there was great variation between the boroughs in terms of the proportion of cases investigated in each category. This reflects variations in reporting in each borough and variation in boroughspecific incidence rates. Bull. N. Y. Acad. Med.
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NURSE-EPIDEMIOLOGY PROGRAM
TABLE II. INVESTIGATION TIME* FOR CASES OF HEPATITIS IN DAYS BY EPIDEMIOLOGIST, NEW YORK CITY, 1970
Borough
Epidemiologist
Median
Mean
Mode
Range 1-67 1-64 1-50 1-41 1-12
Bronx
No. No. No. No. No.
1 2 3 4 5
7 9 12 12 4
10.0 11.6 14.5 15.4 4.0
6.7 7.0 1.0 8.0 5.0
Brooklyn
No. No. No. No. No. No. No. No.
6 7 8 9 10 11 12 13
4 7 8 8 8 10 10 12
4.1 6.7 7.8 8.3 8.6 9.2 9.6 13.4
5.0 7.0 7.0 8.0 6.0 12.0 10.0
No. No. No. No. No. No. No.
14 15 16 17 18 19 20
6 7 7 8 9 10 15
6.5 6.7 7.1 9.9 12.5 11.8 17.0
8.0 7.0 5.0 7.0 7.0 7.0 15.0
2-17 1-14 1-38 1-35
No. No. No. No. No. No. No.
21 22 23 24 25 26 27
2 3 4 5 5 5 6
2.1 3.4 4.5 4.8 5.4 5.6 6.7
2.0 2.0 4.0 4.0 6.0 4.0 5.0
1-7
4-7 1-13 1-18 1-16 1-30
No. 28
41
54.0
34.0
1-249
Manhattan
Queens
Richmond
12.0
1-10
2-12 2-20 2-20 2-20 3-14 3-20 2-30
1-91 1-101
3-50 1-11
*Time elapsed from the assignment of a case to receipt of the final report.
In addition to investigating the four categories of disease listed in Table I, each field epidemiologist also spent 50 sessions (125 hours) per year covering the department's antirabies clinics. Each field epidemiologist also was on call for emergency investigations about four nights per month (5 p.m. to 9 a.m.) and one weekend per month. There was some variation by borough in the number of nights and weekends of call per month. PERFORMANCE OF THE MEDICAL FIELD EPIDEMIOLOGY PROGRAM, 1970 The medical field epidemiologists were grouped by borough, each group being supervised by a borough chief of epidemiology. There was much Vol. 53, No. 6, July-August 1977
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TABLE III. MEAN INVESTIGATION TIME* IN DAYS FOR EPIDEMIOLOGISTS BY DISEASE AND BOROUGH, NEW YORK CITY, 1970 Borough Bronx Brooklyn Manhattan Queens Richmond
Hepatitis
Salmonellosis
Meningitis
Other diseases
10 8 9 4 54
14 7 9 5 42
9 7 12 5 44
5 6 6 4 34
*Time elapsed from the assignment of a case to receipt of the final report.
TABLE IV. ANNUAL NUMBER OF INVESTIGATIONS PER EPIDEMIOLOGIST AND THE ANNUAL COST PER INVESTIGATION BY BOROUGH, NEW YORK CITY, 1970
Borough
Investigations per epidemiologist Average No. Range
Bronx Brooklyn Manhattan Queens Richmond
421 255 276 181 433
New York City
313
396 137 188 19
-
421 376 414 270
Average cost per investigation ($) 26 43 40 61 25
Range in cost of an investigation ($) 24 29 27 41
-
28 80 58 574
39
variation in productivity between the five borough groups as shown in Tables II, III, and IV. There was also a wide variation in the quality of the investigations and of the control measures implemented. These variations were due to unevenness in the productivity of individual epidemiologists and in the quality of the supervision which they received at the borough level. As shown in Table II, the mean investigation time for hepatitis varied from as short a period as 2.1 days to a maximum of 54.0 days. Table III presents the mean investigation times by borough for the four categories of disease. The shortest times were found in Queens and the longest in Richmond, where only one epidemiologist was employed. These data, however, must be viewed against the number of investigations conducted per man in each borough (Table IV). While the Queens epidemiologists completed their investigations in the shortest time, they also had fewer Bull. N. Y. Acad. Med.
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575
investigations to perform per man than any of the other boroughs. Although the one epidemiologist assigned to Richmond had 433 investigations, he took as long as 249 days to complete some, compared to the longest period of 67 days recorded for the Bronx, where epidemiologists had approximately the same number of investigations per man per year. The apparent efficiency of the Queens group of epidemiologists was due basically to their having less work. Because epidemiologists were paid on a preset per-session basis of 350 sessions a year ($11,000), the cost per investigation rose proportionally as the annual number of investigations per man fell. Thus, the average cost of an investigation in Queens was $61.00 in 1970 compared to a low of $25.00 and $26.00 in Richmond and the Bronx, respectively. Field epidemiologists when presented with these data argued that they also were being paid for their availability and not per unit of work produced. The department said that careful study had shown that field epidemiologists rarely could be found on the nights and weekends when they were assigned coverage duty and that in effect the department's small full-time staff was dealing with the majority of problems which arose on weekends and at night. To have enforced and properly supervised this coverage system would have entailed an expenditure in personnel services which would have outweighed its value and cost. In 1970 the field epidemiology program was costing the Department of Health an average of $444,000 per year. The part-time services provided were mainly routinized case investigations of hepatitis, salmonellosis, and meningitis. Whenever serious outbreaks occurred, such as those of trichinosis, diphtheria, and botulism, the small full-time staff had to take over, since the part-time epidemiologists could not manage these problems adequately during the 2 1/2 hours a day they were employed. In 1972 the routine investigation of cases of salmonellosis was discontinued. Up to then cases usually were investigated because of a reported positive stool culture. Such reports did not reach the department until a week or more after the illness. Consequently, these routine investigations rarely produced anything which could have been profitable from an epidemiologic point of view. Since 1972 only certain outbreaks and clusters of cases have been investigated. This change in policy reduced the case load of field epidemiologists by almost 20%. Their routine investigations of hepatitis, meningitis, and other diseases produced mainly case-specific clinical details, but little or no epidemiologic data. In 1974 the Department of Health modified Vol. 53, No. 6, July-August 1977
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TABLE V. DUTIES OF PUBLIC HEALTH NURSE-EPIDEMIOLOGISTS, NEW YORK CITY DEPARTMENT OF HEALTH, 1975 1) Provide information regarding the incidence, control, and prevention of infectious diseases to medical practitioners and the general public 2) Supervise and participate in epidemiological investigations to determine sources of infection or vehicles of transmission 3) Institute immediate control and preventive measures such as isolation of cases and immunization and quarantine of contacts in outbreaks of disease 4) Assist hospitals in the investigation and control of nosocomial infections 5) Coordinate outbreak-control measures with local health officials, hospital infectioncontrol committees, and epidemiologists 6) Participate in the education of persons involved in the prevention of infectious disease 7) Serve as preceptors or role models in field-practice programs for nursing and medical students 8) Act as consultants in epidemiology to other professional disciplines and the community 9) Conduct studies and investigations of public-health problems involving noncommunicable diseases and environmental hazards
its antirabies treatment policy in order to bring it into line with known epidemiologic data. This greatly reduced the need for antirabies clinics and for coverage of them by epidemiologists. Because of these facts, the cost of the program, the fact that the program was ill-adapted to existing needs, and the department's inability to recruit personnel, it was decided to establish a new program staffed by full-time public health nurse-epidemiologists. SELECTION OF NURSES FOR PROGRAM
All candidates were registered professional nurses licensed to practice in the United States and graduates of approved baccalaureate nursing programs. The candidates were recruited exclusively from among the 460 Public Health Nurses then working in the Department of Health's Bureau of Public Health Nursing. The skills acquired by public-health nurses who work in the Department of Health's district health centers and clinics and the specific experiences they have from various epidemiologic field investigations throughout the city provide them with an excellent background for training as public health epidemiologists. The 10 candidates who were selected had an average of 4.01 years (median 2.83 years) of experience in public health nursing. In addition, all candidates were required to have some hospital experience. This provides a sound background in the medical, laboratory, administrative, and recording procedures of hospitals which is needed in investigating reports of infectious diseases. The average number Bull. N. Y. Acad. Med.
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577
of years of hospital-based nursing experience prior to entrance into public health nursing was 9.35 years (median 9.00 years). The over-all average in both types of nursing experience for the 10 candidates was 13.35 years (median 11.83 years). Selection was limited to public-health nurses who had taken courses in microbiology, biostatistics, and epidemiology in nursing school and who had received at least a B average in each of these subjects. Since these courses were to be part of the first semester's curriculum, it was thought that a sound background in these subjects would allow for concentrated discussion of those principles applicable to the work of the epidemiologist. Finally, each candidate's work performance records were reviewed. Annual supervisor reports from the Bureau of Public Health Nursing were examined, special attention being given to punctuality, self-direction, competence in nursing practice, and motivation for continued learning. The final selection of the candidates was based on all of these qualifications. THE NURSE-EPIDEMIOLOGY TRAINING PROGRAM
The training program lasted 30 weeks; it began with six weeks of lectures, followed by 12 weeks of a closely supervised work-study (internship) experience, and concluded with 12 weeks of field work. The program was designed to build upon the nurses' background in public health so that they would be extremely competent to perform the duties of public health epidemiologists (listed in Table V). The initial six-week didactic period consisted of an intense presentation of basic concepts which integrated lectures, problem-solving seminars, and discussion workshops based on the lectures. The course in biostatistics stressed the collection, tabulation, graphing, and comparison of vital statistics. The students were also introduced to elementary sampling techniques and life-expectancy tables. Great emphasis was placed on the development of practical skills needed to interpret and present data effec-
tively. The course in epidemiology was divided into two equal segments. During the first three weeks the nurses were taught principles and methods of epidemiology. These included concepts of cause, patterns of disease occurrence, genetic and environmental determinants of disease, and methods of study (cohort, case-control, clinical trials). The students also were introduced to screening, principles of immunization and chemoprophylaxVol. 53, No. 6, July-August 1977
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is, and selected aspects of chronic and congenital disease. The second three-week period was an in-depth presentation of the epidemiology and importance to public health of specific infectious diseases that the public health epidemiologists might encounter during their future assignments. The diseases discussed included food-borne and water-borne infections, viral diseases of the gastrointestinal tract-including hepatitis, diseases spread by arthropod vectors, rabies, tropical diseases and zoonoses, acute and chronic respiratory diseases, sexually transmitted diseases, and nosocomial infections. The course in microbiology complemented the epidemiology of infectious diseases by familiarizing the students with the laboratory techniques necessary to augment their epidemiologic investigations through lectures and practical experience. Students learned methods for microbial sampling of the environment, respiratory infections, and food-borne and water-borne diseases. They reviewed basic concepts in the interpretation of bacteriologic, virologic, and serologic findings. Finally, they participated in survey exercises to familiarize themselves with the bacteriologic flora in the hospital environment and the respiratory tract. The course in environmental sanitation emphasized the role of air, water, heating, ventilation, air conditioning, illumination, noise, and radiation in health-related problems. The students were familiarized with the problems of pest control, animals, drugs, and toxins such as lead poisoning. They also learned principles of inspection, sampling, standards, and testing necessary to quantitate environmental hazards. The course in administration and resources was oriented toward defining the role of the nurse-epidemiologist in New York City. The organization of health services on the city, state, and federal levels was described. The students also reviewed the New York City Health Code and the specific health forms and methods of collecting data and analyzing statistics that they would use. The work-study experience was divided into three periods of four weeks each. Two periods were spent working under the supervision of a hospital nurse-epidemiologist. A total of four hospitals participated in the program; two students were assigned to one hospital for a four-week period and then rotated to another hospital for a second four weeks. One day each week the students returned for a planned program of continuing education; this included lectures, seminars, tutorial sessions, case presentations, and field trips. Bull. N. Y. Acad. Med.
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During, this phase of the internship the students were exposed to the knowledge, skills, and attitudes of hospital nurse-epidemiologists and were able to gain an understanding of those problems inherent in dealing with hospital-associated infections and outbreaks. Under the direct supervision of hospital nurse-epidemiologists, students were given the opportunity to make rounds of nursing units for the purpose of casefinding, to determine the suitability of procedures for isolation, to maintain records of patients with infections, to identify problems in employees, and to teach others about infection-control techniques and problems. In addition, the students were asked to help identify and investigate possible sources of infection within the hospital, report required diseases to the City of New York Department of Health, assist in developing the monthly report of infections, attend various meetings and conferences relevant to the control of infection, and be aware of environmental hazards (including problems concerning sterilization and disinfection). The third four-week period was spent at the Department of Health's Bureau of Infectious Disease Control. Students observed the functioning of the bureau's central office as reports of infectious disease were received, confirmed, tabulated. assigned. investigated, and completed. Students became familiar with the employees of the bureau as well as the various forms used by secretarial, clerical, microbiological, and field personnel. Under supervision of full-time epidemiologists, students were assigned to answer telephone calls from physicians, hospitals, and citizens on problems related to infectious diseases. Toward the end of the four-week period the students accompanied the full-time physician-epidemiologists in investigations of case reports or outbreaks of various infectious diseases. Throughout the 12-week work-study experience, one day each week was devoted to planned continuing education. Morning sessions included two segments of two hours each. The initial two-hour segment consisted of a critical analysis of a recent journal article dealing with an outbreak or epidemic of a disease. Each week one student was assigned to review an article in depth and comment on the design. statistical methods, and conclusions of the article. All students participated in the discussion of the article. In the second two-hour segment another student presented a summary of the clinical, microbiological, and epidemiological aspects of a specific infectious disease. In most cases the journal article and the infectious disease topic were closely related. Afternoon sessions consisted of field trips to various health agencies, Vol. 53, No. 6, July-August 1977
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including the Department of Health's Bureau of Laboratories, Poison Control Center, Medical Examiner's Office, Tropical Disease Clinics, and Restaurant Inspection Bureau, as well as a field trip to the Quarantine Center at Kennedy Airport. During these sessions the students were encouraged to ask questions about the mission of each agency and how it related to their future work. Once their training program was completed, the nurse-epidemiologists were awarded conjoint diplomas from the New York City Department of Health and the Cornell University Medical Center-New York Hospital School of Nursing. They were then assigned to work full-time in one of five borough offices under the supervision of the department's full-time central office staff and the part-time physicians who serve as borough chiefs. COMPARATIVE WORK PERFORMANCE OF THE NURSE- EPIDEMIOLOGISTS AND PART- TIME PHYSICIAN-EPIDEMIOLOGISTS, 1975
To compare the work performance of the nurse-epidemiologists and the part-time physician-epidemiologists a retrospective analysis of certain of their investigations was undertaken in December 1975. This analysis was limited to investigation reports submitted by both groups on viral hepatitis and infections of the central nervous system. All reports of these two types of investigations submitted since January 1, 1975 were reviewed consecutively until 1,000 cases of viral hepatitis and 500 cases of central-nervoussystem infections were collected. These reports represent approximately 90% and 95%, respectively, of the year's total cases for these two conditions. Two parameters were examined in these reports, one quantitative and the other qualitative. The quantitative measure consisted of the average number of days elapsed between assignment of the case to an epidemiologist and submission of the final report. The latter, a qualitative measure, consisted of the presence of comments on the report forms. Case reports often require some detailed comments in order to amplify the data which is coded on the investigation form. For the purpose of this analysis, case reports lacking such comments were considered to be inadequately completed. Case reports of viral hepatitis were also examined to learn whether the patient had been tested for hepatitis B antigen and whether the result was positive, negative, or pending. Bull. N. Y. Acad. Med.
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NURSE-EPIDEMIOLOGY~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ TABLE VI. COMPARATIVE WORK PERFORMANCE OF NURSE-EPIDEMIOLOGISTS AND PART-TIME PHYSICIAN-EPIDEMIOLOGISTS, CITY OF NEW YORK DEPARTMENT OF HEALTH, 1975 Viral hepatitis Average No. of days to cormNumber plete of investireports gation
Central-nervous-system infections Average No. of
days to
Reports Reports with comments
with cormments on hepatitis B
com-
Number plete of investireports gation
Reports with comments
(%)
antigen (%)
7.95
51.4
13.2
304
22.6
54.7
7.40
98.8*
75.5*
196
7.30*
98.9*
(%)
Part-time
physician-
epidemiol776 ogists Nurseepidemiol224 ogists *P=
THE NEW YORK CITY NURSE - EPIDEMIOLOGY PROGRAM PASCAL JAMES IMPERATO, M.D., M.P.H. & T.M. Commissioner of Health City of New York
LEWIS M. DRUSIN, M.D., M.P.H. Associate Professor of Public Health Assistant Professor of Medicine Cornell University Medical College
JOHN S. MARR, M.D., M.P.H. Director, Bureau of Preventable Diseases City of New York Department of Health
ELEANOR C. LAMBERTSEN, Ed.D. Dean Cornell University-New York Hospital School of Nursing
BARBARA TOPFF OLSTEIN, M.A., R.N. Nurse Epidemiologist Instructor Division of Continuing Education Cornell University-New York Hospital School of Nursing New York, N.Y.
T HE epidemiology services of the City of New York Department of Health were first developed in the latter half of the 19th century as part of the department's Division of Contagious Diseases. In the first half of this century a division of epidemiologic services was developed within the Bureau of Preventable Diseases and its successor, the Bureau of Infectious Disease Control. The epidemiologic activities of the City of New York Department of Health include surveillance of disease, the investigation of cases and outbreaks of specific communicable diseases, and the implementation of control measures to stop or minimize the spread of disease, which includes immunization activities and coordination with local, state, and federal agencies. Until 1975 the Department of Health staffed its epidemiology unit with Address for reprint requests: Pascal J. New York, N.Y. 10013.
Vol. 53, No. 6, July-August 1977
Imperato, M.D., Commissioner of Health, 125 Worth Street,
570
AND OTHERS J. IMPERATO P. J. IMPERATO
570P.
AND
OTHERS
physicians who were primarily clinicians. This pattern, originally established in the latter part of the 19th century, met the city's needs until the 1950s. In 1972, when the department's epidemiologic activities came under new direction, studies clearly indicated that the department's epidemiologic services were costly and less than effective. In order to make the department more responsive to the city's current needs in the control of communicable diseases, it was decided to reorganize the Division of Epidemiologic Intelligence and to replace its parttime clinicians by full-time nurse-epidemiologists. This paper describes the process and its results. THE DEVELOPMENT OF EPIDEMIOLOGIC SERVICES
Epidemiologic activities have been carried out in New York City since the 18th century. It was not until the latter part of the 19th century that the Department of Health institutionalized these activities within the administrative framework of a Division of Contagious Diseases. A principal activity of this division and its successor organizations was the accurate clinical diagnosis of reported cases of communicable disease. Reports of specific communicable diseases were not accepted on their face value, especially in the years before accurate confirmatory laboratory tests were widely available. This meant that individual patients had to be examined by skilled and experienced diagnosticians and the diagnosis of the reporting physician either upheld or rejected on clinical grounds. Control measures hinged upon the confirmatory diagnosis; for this reason the Department of Health developed a cadre of well-trained diagnostician-epidemiologists. These epidemiologists were clinical physicians with diagnostic acumen. From the 1920s through the 1950s the Department of Health was able to recruit and retain sufficient numbers of physician-epidemiologists. This was especially true during the years of the Great Depression, when the steady income of municipal employment was an inducement. After World War II the older members of the staff remained since they had a large investment in pensions. But it became increasingly difficult to recruit younger physicians because of the relatively low salaries offered by the department compared to the potential remuneration of private practice and the incomes available in private and university employment. In order to deal with the problem of recruitment, the department's Bureau of Preventable Diseases came to rely increasingly on the services Bull. N. Y. Acad. Med.
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571
of part-time physicians who were paid for each session. The majority of these physicians were pediatricians, internists, and general practitioners in private practice who worked an average of 2 1/2 hours per day for the Bureau of Preventable Diseases.
EPIDEMIOLOGIC SERVICES, 1965-1974 By the mid-1960s many of the full-time medical epidemiologists who had entered the Department of Health in the 1930s began to retire. The responsibility for providing epidemiologic services devolved increasingly upon the part-time epidemiologists. This was a less than satisfactory situation, since many types of outbreak require long hours of field work. Part-time staff do not have the time to conduct such investigations properly. Between 1965 and 1974 most of the serious outbreaks were managed by a small nucleus of full-time staff who often served long overtime hours without remuneration. In 1970, 31 part-time field epidemiologists were employed by the Department of Health. The Division of Epidemiology in which they worked was headed by a full-time medical epidemiologist and staffed with one full-time medical epidemiologist. In addition, the division provided experience and training to one epidemic intelligence service officer from the U.S. Public Health Service Center for Disease Control. The chief of the Division of Epidemiology reported to a full-time medical director of the Bureau of Infectious Disease Control. By 1972 the Division of Epidemiology had lost both its chief and its remaining full-time epidemiologist, thereby causing an upward shift of operational responsibility to the director of the Bureau of Infectious Disease Control. This person was also responsible for administering the Division of Tropical Medicine, which operates four clinics in the city and provides for 25,000 visits per year, the Division of Veterinary Medicine, and the Immunization Program. In spite of intensive efforts, the department was unable to attract any candidates for either the position of chief epidemiologist or the four full-time epidemiologist positions. There were several reasons for this inability to recruit. Salary levels were locked into the New York City civil service system and were about 25% less than those for comparable positions in state and national governments. Even with parity salaries it is difficult to attract professionals into New York City because of the relatively high cost of living and the high state and city income taxes. Also, Vol. 53, No. 6, July-August 1977
P. J. IMPERATO AND OTHERS
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OTHERS
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TABLE I. FIELD ACTIVITIES OF MEDICAL EPIDEMIOLOGISTS BY DISEASE AND BOROUGH, NEW YORK CITY, 1970
Other diseases Meningitis Salmonellosis Hepatitis Total number of cases % of total % of total % of total % of total assigned for Borough investigation Number in borough Number in borough Number in borough Number in borough
1,934
1,268 454
496 1,196 950 788 371
30% 52% 49% 62% 82%
403 517 399 143 26
24% 23% 21% 11% 6%
442 187 379 107 24
26% 8% 19% 9% 5%
344 392 206 230 33
20% 17% 11% 18% 7%
7,633
3,801
50%
1,488
19%
1,139
15%
1,205
16%
Bronx Brooklyn Manhattan Queens Richmond
1,685 2,292
Total
there are only a limited number of medical epidemiologists in the United States; the steady decline in the incidence of major communicable diseases over the past two decades has made communicable disease epidemiology increasingly unattractive to medical graduates. Thus, fewer physicians enter the field and the pool of candidates diminishes. At the same time that the department was unable to recruit full-time epidemiologists, the part-time staff began to diminish through retirement. By 1972 there were five fewer part-time epidemiologists than there had been in 1970. The department encountered the same difficulties in recruiting part-time clinicians for these positions as it had when it tried to find full-time staff. The major reasons for the department's inability to recruit part-time physicians were the noncompetitive remuneration offered and the unwillingness of physicians to carry out field investigations in many areas of the city for fear of physical injury. This was not an imaginary risk; several field epidemiologists already had been hurt on one or more occasions, sometimes by the individuals they were trying to help. FUNCTION OF MEDICAL EPIDEMIOLOGISTS, 1970
In 1970, 50% of all cases investigated by field epidemiologists in New York City were of hepatitis (Table I), 19% salmonellosis, 15% meningitis, and 16% other diseases such as trichinosis, ornithosis, and food intoxication. As shown in Table I, there was great variation between the boroughs in terms of the proportion of cases investigated in each category. This reflects variations in reporting in each borough and variation in boroughspecific incidence rates. Bull. N. Y. Acad. Med.
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NURSE-EPIDEMIOLOGY PROGRAM
TABLE II. INVESTIGATION TIME* FOR CASES OF HEPATITIS IN DAYS BY EPIDEMIOLOGIST, NEW YORK CITY, 1970
Borough
Epidemiologist
Median
Mean
Mode
Range 1-67 1-64 1-50 1-41 1-12
Bronx
No. No. No. No. No.
1 2 3 4 5
7 9 12 12 4
10.0 11.6 14.5 15.4 4.0
6.7 7.0 1.0 8.0 5.0
Brooklyn
No. No. No. No. No. No. No. No.
6 7 8 9 10 11 12 13
4 7 8 8 8 10 10 12
4.1 6.7 7.8 8.3 8.6 9.2 9.6 13.4
5.0 7.0 7.0 8.0 6.0 12.0 10.0
No. No. No. No. No. No. No.
14 15 16 17 18 19 20
6 7 7 8 9 10 15
6.5 6.7 7.1 9.9 12.5 11.8 17.0
8.0 7.0 5.0 7.0 7.0 7.0 15.0
2-17 1-14 1-38 1-35
No. No. No. No. No. No. No.
21 22 23 24 25 26 27
2 3 4 5 5 5 6
2.1 3.4 4.5 4.8 5.4 5.6 6.7
2.0 2.0 4.0 4.0 6.0 4.0 5.0
1-7
4-7 1-13 1-18 1-16 1-30
No. 28
41
54.0
34.0
1-249
Manhattan
Queens
Richmond
12.0
1-10
2-12 2-20 2-20 2-20 3-14 3-20 2-30
1-91 1-101
3-50 1-11
*Time elapsed from the assignment of a case to receipt of the final report.
In addition to investigating the four categories of disease listed in Table I, each field epidemiologist also spent 50 sessions (125 hours) per year covering the department's antirabies clinics. Each field epidemiologist also was on call for emergency investigations about four nights per month (5 p.m. to 9 a.m.) and one weekend per month. There was some variation by borough in the number of nights and weekends of call per month. PERFORMANCE OF THE MEDICAL FIELD EPIDEMIOLOGY PROGRAM, 1970 The medical field epidemiologists were grouped by borough, each group being supervised by a borough chief of epidemiology. There was much Vol. 53, No. 6, July-August 1977
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574
TABLE III. MEAN INVESTIGATION TIME* IN DAYS FOR EPIDEMIOLOGISTS BY DISEASE AND BOROUGH, NEW YORK CITY, 1970 Borough Bronx Brooklyn Manhattan Queens Richmond
Hepatitis
Salmonellosis
Meningitis
Other diseases
10 8 9 4 54
14 7 9 5 42
9 7 12 5 44
5 6 6 4 34
*Time elapsed from the assignment of a case to receipt of the final report.
TABLE IV. ANNUAL NUMBER OF INVESTIGATIONS PER EPIDEMIOLOGIST AND THE ANNUAL COST PER INVESTIGATION BY BOROUGH, NEW YORK CITY, 1970
Borough
Investigations per epidemiologist Average No. Range
Bronx Brooklyn Manhattan Queens Richmond
421 255 276 181 433
New York City
313
396 137 188 19
-
421 376 414 270
Average cost per investigation ($) 26 43 40 61 25
Range in cost of an investigation ($) 24 29 27 41
-
28 80 58 574
39
variation in productivity between the five borough groups as shown in Tables II, III, and IV. There was also a wide variation in the quality of the investigations and of the control measures implemented. These variations were due to unevenness in the productivity of individual epidemiologists and in the quality of the supervision which they received at the borough level. As shown in Table II, the mean investigation time for hepatitis varied from as short a period as 2.1 days to a maximum of 54.0 days. Table III presents the mean investigation times by borough for the four categories of disease. The shortest times were found in Queens and the longest in Richmond, where only one epidemiologist was employed. These data, however, must be viewed against the number of investigations conducted per man in each borough (Table IV). While the Queens epidemiologists completed their investigations in the shortest time, they also had fewer Bull. N. Y. Acad. Med.
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575
investigations to perform per man than any of the other boroughs. Although the one epidemiologist assigned to Richmond had 433 investigations, he took as long as 249 days to complete some, compared to the longest period of 67 days recorded for the Bronx, where epidemiologists had approximately the same number of investigations per man per year. The apparent efficiency of the Queens group of epidemiologists was due basically to their having less work. Because epidemiologists were paid on a preset per-session basis of 350 sessions a year ($11,000), the cost per investigation rose proportionally as the annual number of investigations per man fell. Thus, the average cost of an investigation in Queens was $61.00 in 1970 compared to a low of $25.00 and $26.00 in Richmond and the Bronx, respectively. Field epidemiologists when presented with these data argued that they also were being paid for their availability and not per unit of work produced. The department said that careful study had shown that field epidemiologists rarely could be found on the nights and weekends when they were assigned coverage duty and that in effect the department's small full-time staff was dealing with the majority of problems which arose on weekends and at night. To have enforced and properly supervised this coverage system would have entailed an expenditure in personnel services which would have outweighed its value and cost. In 1970 the field epidemiology program was costing the Department of Health an average of $444,000 per year. The part-time services provided were mainly routinized case investigations of hepatitis, salmonellosis, and meningitis. Whenever serious outbreaks occurred, such as those of trichinosis, diphtheria, and botulism, the small full-time staff had to take over, since the part-time epidemiologists could not manage these problems adequately during the 2 1/2 hours a day they were employed. In 1972 the routine investigation of cases of salmonellosis was discontinued. Up to then cases usually were investigated because of a reported positive stool culture. Such reports did not reach the department until a week or more after the illness. Consequently, these routine investigations rarely produced anything which could have been profitable from an epidemiologic point of view. Since 1972 only certain outbreaks and clusters of cases have been investigated. This change in policy reduced the case load of field epidemiologists by almost 20%. Their routine investigations of hepatitis, meningitis, and other diseases produced mainly case-specific clinical details, but little or no epidemiologic data. In 1974 the Department of Health modified Vol. 53, No. 6, July-August 1977
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TABLE V. DUTIES OF PUBLIC HEALTH NURSE-EPIDEMIOLOGISTS, NEW YORK CITY DEPARTMENT OF HEALTH, 1975 1) Provide information regarding the incidence, control, and prevention of infectious diseases to medical practitioners and the general public 2) Supervise and participate in epidemiological investigations to determine sources of infection or vehicles of transmission 3) Institute immediate control and preventive measures such as isolation of cases and immunization and quarantine of contacts in outbreaks of disease 4) Assist hospitals in the investigation and control of nosocomial infections 5) Coordinate outbreak-control measures with local health officials, hospital infectioncontrol committees, and epidemiologists 6) Participate in the education of persons involved in the prevention of infectious disease 7) Serve as preceptors or role models in field-practice programs for nursing and medical students 8) Act as consultants in epidemiology to other professional disciplines and the community 9) Conduct studies and investigations of public-health problems involving noncommunicable diseases and environmental hazards
its antirabies treatment policy in order to bring it into line with known epidemiologic data. This greatly reduced the need for antirabies clinics and for coverage of them by epidemiologists. Because of these facts, the cost of the program, the fact that the program was ill-adapted to existing needs, and the department's inability to recruit personnel, it was decided to establish a new program staffed by full-time public health nurse-epidemiologists. SELECTION OF NURSES FOR PROGRAM
All candidates were registered professional nurses licensed to practice in the United States and graduates of approved baccalaureate nursing programs. The candidates were recruited exclusively from among the 460 Public Health Nurses then working in the Department of Health's Bureau of Public Health Nursing. The skills acquired by public-health nurses who work in the Department of Health's district health centers and clinics and the specific experiences they have from various epidemiologic field investigations throughout the city provide them with an excellent background for training as public health epidemiologists. The 10 candidates who were selected had an average of 4.01 years (median 2.83 years) of experience in public health nursing. In addition, all candidates were required to have some hospital experience. This provides a sound background in the medical, laboratory, administrative, and recording procedures of hospitals which is needed in investigating reports of infectious diseases. The average number Bull. N. Y. Acad. Med.
NURSE-EPIDEMIOLOGY PROGRAM
577
of years of hospital-based nursing experience prior to entrance into public health nursing was 9.35 years (median 9.00 years). The over-all average in both types of nursing experience for the 10 candidates was 13.35 years (median 11.83 years). Selection was limited to public-health nurses who had taken courses in microbiology, biostatistics, and epidemiology in nursing school and who had received at least a B average in each of these subjects. Since these courses were to be part of the first semester's curriculum, it was thought that a sound background in these subjects would allow for concentrated discussion of those principles applicable to the work of the epidemiologist. Finally, each candidate's work performance records were reviewed. Annual supervisor reports from the Bureau of Public Health Nursing were examined, special attention being given to punctuality, self-direction, competence in nursing practice, and motivation for continued learning. The final selection of the candidates was based on all of these qualifications. THE NURSE-EPIDEMIOLOGY TRAINING PROGRAM
The training program lasted 30 weeks; it began with six weeks of lectures, followed by 12 weeks of a closely supervised work-study (internship) experience, and concluded with 12 weeks of field work. The program was designed to build upon the nurses' background in public health so that they would be extremely competent to perform the duties of public health epidemiologists (listed in Table V). The initial six-week didactic period consisted of an intense presentation of basic concepts which integrated lectures, problem-solving seminars, and discussion workshops based on the lectures. The course in biostatistics stressed the collection, tabulation, graphing, and comparison of vital statistics. The students were also introduced to elementary sampling techniques and life-expectancy tables. Great emphasis was placed on the development of practical skills needed to interpret and present data effec-
tively. The course in epidemiology was divided into two equal segments. During the first three weeks the nurses were taught principles and methods of epidemiology. These included concepts of cause, patterns of disease occurrence, genetic and environmental determinants of disease, and methods of study (cohort, case-control, clinical trials). The students also were introduced to screening, principles of immunization and chemoprophylaxVol. 53, No. 6, July-August 1977
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is, and selected aspects of chronic and congenital disease. The second three-week period was an in-depth presentation of the epidemiology and importance to public health of specific infectious diseases that the public health epidemiologists might encounter during their future assignments. The diseases discussed included food-borne and water-borne infections, viral diseases of the gastrointestinal tract-including hepatitis, diseases spread by arthropod vectors, rabies, tropical diseases and zoonoses, acute and chronic respiratory diseases, sexually transmitted diseases, and nosocomial infections. The course in microbiology complemented the epidemiology of infectious diseases by familiarizing the students with the laboratory techniques necessary to augment their epidemiologic investigations through lectures and practical experience. Students learned methods for microbial sampling of the environment, respiratory infections, and food-borne and water-borne diseases. They reviewed basic concepts in the interpretation of bacteriologic, virologic, and serologic findings. Finally, they participated in survey exercises to familiarize themselves with the bacteriologic flora in the hospital environment and the respiratory tract. The course in environmental sanitation emphasized the role of air, water, heating, ventilation, air conditioning, illumination, noise, and radiation in health-related problems. The students were familiarized with the problems of pest control, animals, drugs, and toxins such as lead poisoning. They also learned principles of inspection, sampling, standards, and testing necessary to quantitate environmental hazards. The course in administration and resources was oriented toward defining the role of the nurse-epidemiologist in New York City. The organization of health services on the city, state, and federal levels was described. The students also reviewed the New York City Health Code and the specific health forms and methods of collecting data and analyzing statistics that they would use. The work-study experience was divided into three periods of four weeks each. Two periods were spent working under the supervision of a hospital nurse-epidemiologist. A total of four hospitals participated in the program; two students were assigned to one hospital for a four-week period and then rotated to another hospital for a second four weeks. One day each week the students returned for a planned program of continuing education; this included lectures, seminars, tutorial sessions, case presentations, and field trips. Bull. N. Y. Acad. Med.
NURSE-EPIDEMIOLOGY PROGRAM
579
During, this phase of the internship the students were exposed to the knowledge, skills, and attitudes of hospital nurse-epidemiologists and were able to gain an understanding of those problems inherent in dealing with hospital-associated infections and outbreaks. Under the direct supervision of hospital nurse-epidemiologists, students were given the opportunity to make rounds of nursing units for the purpose of casefinding, to determine the suitability of procedures for isolation, to maintain records of patients with infections, to identify problems in employees, and to teach others about infection-control techniques and problems. In addition, the students were asked to help identify and investigate possible sources of infection within the hospital, report required diseases to the City of New York Department of Health, assist in developing the monthly report of infections, attend various meetings and conferences relevant to the control of infection, and be aware of environmental hazards (including problems concerning sterilization and disinfection). The third four-week period was spent at the Department of Health's Bureau of Infectious Disease Control. Students observed the functioning of the bureau's central office as reports of infectious disease were received, confirmed, tabulated. assigned. investigated, and completed. Students became familiar with the employees of the bureau as well as the various forms used by secretarial, clerical, microbiological, and field personnel. Under supervision of full-time epidemiologists, students were assigned to answer telephone calls from physicians, hospitals, and citizens on problems related to infectious diseases. Toward the end of the four-week period the students accompanied the full-time physician-epidemiologists in investigations of case reports or outbreaks of various infectious diseases. Throughout the 12-week work-study experience, one day each week was devoted to planned continuing education. Morning sessions included two segments of two hours each. The initial two-hour segment consisted of a critical analysis of a recent journal article dealing with an outbreak or epidemic of a disease. Each week one student was assigned to review an article in depth and comment on the design. statistical methods, and conclusions of the article. All students participated in the discussion of the article. In the second two-hour segment another student presented a summary of the clinical, microbiological, and epidemiological aspects of a specific infectious disease. In most cases the journal article and the infectious disease topic were closely related. Afternoon sessions consisted of field trips to various health agencies, Vol. 53, No. 6, July-August 1977
580
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P. J. IMPERATO AND OTHERS
including the Department of Health's Bureau of Laboratories, Poison Control Center, Medical Examiner's Office, Tropical Disease Clinics, and Restaurant Inspection Bureau, as well as a field trip to the Quarantine Center at Kennedy Airport. During these sessions the students were encouraged to ask questions about the mission of each agency and how it related to their future work. Once their training program was completed, the nurse-epidemiologists were awarded conjoint diplomas from the New York City Department of Health and the Cornell University Medical Center-New York Hospital School of Nursing. They were then assigned to work full-time in one of five borough offices under the supervision of the department's full-time central office staff and the part-time physicians who serve as borough chiefs. COMPARATIVE WORK PERFORMANCE OF THE NURSE- EPIDEMIOLOGISTS AND PART- TIME PHYSICIAN-EPIDEMIOLOGISTS, 1975
To compare the work performance of the nurse-epidemiologists and the part-time physician-epidemiologists a retrospective analysis of certain of their investigations was undertaken in December 1975. This analysis was limited to investigation reports submitted by both groups on viral hepatitis and infections of the central nervous system. All reports of these two types of investigations submitted since January 1, 1975 were reviewed consecutively until 1,000 cases of viral hepatitis and 500 cases of central-nervoussystem infections were collected. These reports represent approximately 90% and 95%, respectively, of the year's total cases for these two conditions. Two parameters were examined in these reports, one quantitative and the other qualitative. The quantitative measure consisted of the average number of days elapsed between assignment of the case to an epidemiologist and submission of the final report. The latter, a qualitative measure, consisted of the presence of comments on the report forms. Case reports often require some detailed comments in order to amplify the data which is coded on the investigation form. For the purpose of this analysis, case reports lacking such comments were considered to be inadequately completed. Case reports of viral hepatitis were also examined to learn whether the patient had been tested for hepatitis B antigen and whether the result was positive, negative, or pending. Bull. N. Y. Acad. Med.
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581
NURSE-EPIDEMIOLOGY~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ TABLE VI. COMPARATIVE WORK PERFORMANCE OF NURSE-EPIDEMIOLOGISTS AND PART-TIME PHYSICIAN-EPIDEMIOLOGISTS, CITY OF NEW YORK DEPARTMENT OF HEALTH, 1975 Viral hepatitis Average No. of days to cormNumber plete of investireports gation
Central-nervous-system infections Average No. of
days to
Reports Reports with comments
with cormments on hepatitis B
com-
Number plete of investireports gation
Reports with comments
(%)
antigen (%)
7.95
51.4
13.2
304
22.6
54.7
7.40
98.8*
75.5*
196
7.30*
98.9*
(%)
Part-time
physician-
epidemiol776 ogists Nurseepidemiol224 ogists *P=
