Jeremiah J. German, M.A., and Joyce Mamon, Ph.D. and the contributions of Monique ... West, S.K., B.M. Brandon, G.A. Chase, P.D. Stolley,. S. Shapiro and R.E. ...
PRODUCTIVITY ANALYSES OF AMBULATORY CARE PROVIDERS: A METHOD BASED ON OBSERVATIONAL AND INFORMATION SYSTEM DATA Elizabeth A. Skinner, M.S.W., Donald M. Steinwachs, Ph.D. David Salkever, Ph.D., and Harvey Katz, M.D. Health Services Research and Development Center The Johns Hopkins Medical Institutions
taken to compare the productivity of physicians and nurse practitioners working in a pediatric clinic of an HMO. The research effort focused heavily on whether a methodology could be developed that relied to the greatest extent on readily available information, was relatively inexpensive to implement, and that would permit analysis of episodes of ambulatory care. The result of these efforts combined data from an established management information system with time estimates derived from a small observation study. The principal characteristics of the method developed by our team
Abstract: The development of a methodology to examine health manpower productivity in an ambulatory care setting is described. The method involves (a) a small observation study, (b) linkage of times for observed visits to data on diagnosis and patient characteristics from an encounter data information system, and (c) analyses performed for episodes of care for different diagnostic categories. The setting for the study was the Department of Pediatrics in the Columbia Medical Plan, a prepaid group practice HMO. The observation study obtained time data for a sample of visits to physicians and nurse practitioners during a two-week period. Applications of the time data are demonstrated in an analysis of variations in direct patient care times for each provider type. The process of identifying episodes of care for otitis media and sore throat, two common pediatric problems, and calculation of costs related to the episodes are described, and variations in total episode costs are explored. The strengths and limitations of the methodology are discussed.
are:
(1) Observation of a sample of provider's time spent in the setting; (2) Linkage of times for each observed visit to information on diagnosis, procedures and patient characteristics contained in the information system; and (3) Analysis of episodes of care for selected diagnostic categories as well as for different provider types. The interest in the episode of care is an important element of the approach taken in this study. Previous studies in the same pediatric clinic had indicated that visits to nurse practitioners included patients with conditions that fell into diagnostic categories similar to those for physicians' patients, and that they were handling the majority of these visits independently (Steinwachs et al, 1976). Studies focusing on visits, however, do not take into account the whole process of handling one particular medical problem. If it happened, for instance, that nurse practitioners were more likely than physicians to ask their patients to make follow-up visits, then the total cost of the episode of care would be greater for nurse practitioners than for physicians.
Comparisons of costs and productivity of physicians and other health practitioners have been undertaken with increasing frequency in recent years. The impetus for these investigations in ambulatory care settings has arisen from concerns for the efficient and effective use of health manpower as more and more non-physician providers are utilized. These issues are particularly relevant for structured health care delivery programs such as health maintenance organizations that work under capitation payment arrangements. Studies over the past decade have demonstrated that, within their areas of expertise, non-physician health practitioners provide care that is equally as good as that rendered by physicians (e.g. Levine, et al, 1977). In light of these findings, the principal question concerning the use of such practitioners has beccme whether they are in fact a less costly but equally productive way of providing health care.
A key piece of information necessary to evaluate productivity or efficiency is time: how much time does a health care provider, for example, actually spend in direct patient care. Time and motion studies have been used frequently to generate these data, and two different methods have predominated (Wirth, et al, 1977). In continuous observation,
A variety of methods have been used in health manpower productivity analyses, many of which rely heavily on special data collection methods and statistical techniques. These approaches often require sophisticated programming and analytical skills that are likely to be beyond the capabilities of resources available to most health care delivery settings. The method described in this paper was developed in a pilot investigation under-
0195-4210/80/0000-1680$00.75 C 1980
IEEE
an observer monitors and records all activities of a particular provider over a defined time span.
The advantage of this approach is that a considerable amount of detail can be obtained about activities such as record keeping, telephone consultations, personal activities, and the like. It does require, however, a one-to-one ratio of observer and subject. An alternative and frequently used
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method is work sampling in which contacts by telephone or in person are made at random intervals to determine what the provider is doing at the time of contact. This method is attractive because Et requires fewer data collectors, but it too has its drawbacks. In health care settings staffed by a small number of providers, the work sampling approach requires many contacts with each one in order to produce enough observations to be useful analytically. Both of these methods place a not inconsiderable burden on the provider being observed, and both are intrusive in that the observation itself may affect provider activities in ways that are difficult to distinguish.
CMP's information system is composed of two parts. The enrollment file contains data on enrollees' demographic characteristics (age, sex and the like). The encounter data system maintains information on the nature and content of each visit. Data are entered from an encounter form completed at each visit which serves also as an order form for laboratory, x-ray and special procedures. The elements in the system include patient name and enrollment number, appointment status, purpose of the visit, providers seen, laboratory, x-ray and other procedures ordered, problems or diagnoses, and disposition. Prescriptions filled by the Plan's in-house pharmacy are entered as well; it is estimated that all but 5% of prescriptions written by Plan physicians are captured by the system (West, et al, 1977).
These factors were taken into consideration in developing the method described here, as well as some factors that were peculiar to the setting in which we were interested. At bottom, however, we were seeking to develop an approach that could be adapted for use in a variety of different kinds of settings.
There is space on the encounter form to record the duration of the visit or contact. However, the information is requested in 15 minute intervals, not a useful categorization when significant differences between provider type in performing various activities may be a matter of 5 or 6 minutes. An observation study was required to produce time data in sufficient detail to permit the kinds of analyses planned.
The Setting
The setting for this study was the Department of Pediatrics in the Columbia Medical Plan (CMP), a prepaid group practice health maintenance organization serving about 20,000 enrollees in the city of Columbia, Maryland. The Department of Pediatrics is staffed by four full-time equivalent (FTE) physicians, four nurse practitioners, and about four health assistants. The Department has employed nurse practitioners and health assistants since 1969. The annual volume of patient visits to the Department is now about 24,000, with physicians being the primary provider in about 60% of these visits, and nurse practitioners the primary provider in about 40% of the visits.
Observation Study In considering methods for obtaining the time data, the work sampling method was rejected because the small number of providers working in the Department would have necessitated a very large number of contacts for each one. The continuous observation method was rejected also principally because it was considered too intrusive, but also it would have required either a very long data collection period or several observers working simultaneously. In either case, data collection costs would have been relatively high.
Nurse practitioners and physicians both function as independent professionals in providing ambulatory care. Health assistants perform a few well defined clinical tasks such as immunizations but their primary role is scheduling, telephone answering and clerical. They also carry out preliminary tasks during visits to physicians such as bringing patients and their records to examining rooms, weighing and temperature taking. At the time of the study, nurse practitioners usually performed these tasks for their own patients.
The approach adopted was observation of provider activities from stationary "observation posts" in the halls of the Department. This was a compromise since activities occuring inside examination rooms or offices could not be observed. Thus, detailed data on record keeping, telephone calls and the like could not be captured. On the other hand, one observer could keep track of two or, if necessary, three providers at one time.
Appointment sessions are three and a half hours in the morning, and four hours in the afternoon. The schedule allows for two types of appointments, scheduled and walk-in (same-day). Each provider, physicians and nurse practitioners alike, sees his own patients during scheduled visit periods. In walk-in visit periods, at least one physician and one nurse practitioner are on duty. For the most part patients see whoever is available although very young children and those with more serious conditions may be more likely to see physicians. The time alloted for visits is generally 15 minutes for walk-in visits and 30-45 minutes for scheduled visits. Some variations in the time allotted for a visit occur for patients new to the Department, and for consultations.
Another modification in the design was dictated by costs and the architectural layout of the Department. To observe all providers and patients during the data collection period, four observers would have been required, one at each post. To keep costs down, two observers were used and assigned to observation posts in such a way that all providers were covered an equal number of hours. The layout of the Department, allocation of offices and examining rooms to the providers, and traffic flow were major considerations in selecting the locations of the observation posts. Each of three physicians had an office and two or three examining rooms and the observer had to be able to see clearly all of the rooms used by the provider she was
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assigned to cover at a particular time. The nurse practitioners each had an examination room which served also as an office. The provider's room allocations held an advantage for us since in most cases an observer could cover one physician and one nurse practitioner simultaneously.
The observers recorded the time a patient and parent entered the examination room, when the provider left, and when the patient left. Needless to say, there were few visits that were as simple as this to observe. While there was quite a bit of activity going on, the observers quickly became proficient in keeping track of where her assigned providers were and who they were with. Provider activities occurring in between patients were recorded on the form of the last patient seen until such time as a new patient entered an examination room.
In assigning observers to the posts in the hall, several other constraints had to be dealt with. First, scheduling patterns had to be accomodated and second, mornings and afternoons had to be covered equally. As noted earlier, all physicians and nurse practitioners had time periods when they saw patients on a same day or walk-in basis, and visits during such times were allotted 15 minutes as compared to 30 minutes for scheduled visits. Thus, efforts had to be made to observe enough of each type of visit to permit separate analyses. To summarize, assignments of observers were designed to cover equally:
In the two week data collection period, 379 complete patient visits were observed, about half of all visits that were made to the Department in that time span. Visits that were not observed from beginning to end were eliminated from the analysis, although data on provider time expenditures were retained. The unit of analysis was the visit itself in examination of provider times. There were a very few cases where the same patient was observed twice, but each visit was examined separately in the time analysis.
- each provider - scheduled and walk-in visit periods - mornings and afternoons.
Data collection forms were designed to record movement of providers and patients in and out of examination rooms and offices, intervals when patients or providers were alone, consultation between providers, etc. The data collection was patient-based, that is, one form was completed for each patient seen during the time the provider was being observed. For the physicians, this often meant that two or three forms were being filled out simultaneously, since all examination rooms assigned to a physician could contain patients waiting to be seen.
To the observation data were added information from the encounter form as captured by the information system, using the encounter form's unique sequence number as the linkage. These data included history and enrollment numbers; the primary and secondary providers; purpose and duration of the visit; appointment status; dispostion; consultations and/or referrals; up to three diagnoses; laboratory, x-ray and special procedures performed; and prescriptions filled. Using the enrollment number as the link, age and sex as contained in the enrollment file were added as well.
In completing the form, the observer recorded the child's name, who the primary provider was, and how many patients were being seen. This last item was intended to capture situations where a parent brought two or three siblings to be seen and all were in one examination room at the same time.
'Fable 1 displays some characteristics of the patients who were observed in their visits to the Department of Pediatrics. About 30 percent of the children were 2 years of age or younger, and slightly less than half were female. The apparent differences between physicians and nurse practitioners in the age and sex of their patients are not statistically significant. Almost threefourths of all observed children were seen during walk-in periods, and slightly less than half were seen in the morning.
A key piece of information that posed a data collection problem was the encounter form number. Each encounter form had a unique sequence number which was to be the link between the observation data and the information system. We experimented with tags that could be handed to the observer, and other methods, but since the encounter forms and medical records were placed in holders on the doors of examination rooms, the most practical solution was for the observer to get up from her post and
The distribution of diagnoses, limited here to the first of three possible entries on the encounter form, shows that 36 percent of the visits were accounted for by otitis media, sore throat, and upper respiratory conditions. Another 21 percent were visits for well care. The remainder, less than half of all observed visits, were for all other illness and injuries. These distributions are consistent with those for all patient visits during the same period of time. There are some variations by provider type, the largest being for well care which accounted for 30 percent of visits to nurse practitioners, but only 14 percent of phy-
transcribe the number from the form. As a matter of fact, after the first few days of observation, staff of the Department often read off or showed the number to the observer. Observation started when a patient entered an examination room or office, and ended when he left the Department. There were instances when the observer thought the visit was over, only to find the child reappearing some time later. Corrections were made during post-observation edits, and staff of the Department often assisted the observer in identifying these situations.
sician visits. The distributions of time recorded in the observation study are displayed in Table 2. This shows time allocations from the patient's point of view, with the denominators being the total time between
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Characteristics of Observed Patients by Primary Provider Type
TABLE 1:
Primary Provider Nurse
Physician
Practitioner
Total
Total number (of patients
221
158
379
Percent femal(e
42.1
52.9
46.6
Percent aged 2 years or less
27.8
34.9
30.7
Percent morni2 ng visits
46.2
46.2
46.2
Pmp-rasPnrv time vrisits VPav-tant V-La.L b L.LIII r-erCe;elL Ufiel-FU1llW,y
70.1
72.8
71.2
17.6 8.8
13.1 13.1 7.8 30. 1 35.9
15.7
Diagnoses (1) Otitis media Sore throat (2) Upper respiratory conditions Well care Other illness or injury
(1)First
11.1
14.4 48.1
10.6 9.8 20.9 43.1
listed on encounter form.
(2) Includes tonsillitis, URI, asthma, rhinitis,
TABLE 2:
etc.
Allocation of Patients' Time by Primary Provider Tyne
Primary Provider Nurse Practitioner
Physician
Total Patients
Percent
Mean Time
Percent
Mean Time
Percent
Mean Time
Total Patient Visit Time
100.0
29.6
100.0
23.2
100.0
26.9
Direct Patient Care
41.7
12.3
80.4
18.7
55.6
15.0
With Health Assistant
13.7
4.0
1.1
0.3
9.2
2.5
With Other Provider
0.3
0.1
1.2
0.3
0.6
0.2
40.9
12.1
14.8
3.4
31.5
8.5
With Provider Outside Exam Room
0.4
0.1
0.4
0.1
0.4
0.1
Out of Area
3.0
0.9
1.9
0.4
2.6
0.7
Alone in Exam Room
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third were deleted since to include them would have doubled or trebled the times observed for those visits.
entry into an examination room and departure from the clinic. On the average, a patients' visit to the Department lasted 27 minutes, with visits to physicians being about 7 minutes longer than visits to nurse practitioners. Patient activities duri-e the visits were quite different for the two provider types, and reflect to a great extent variations in the ways support services and office space were allocated and in division of labor. For example, patients seeing physicians actually spent only 42 percent of their visit in an examination room or office with the physician they had come to see. An equal amount of time was spent waiting in the examination room alone. The fact that physicians had two and sometimes three patients in different examination rooms simultaneously accounts for much of this. Nurse practitioners, on the other hand, had only one examination room each, and so only one patient at a time couldbe accommodated.
As Table 3 shows, average direct patient caretimes in scheduled visit periods were twice those in walk-in time periods for both nurse practitioners and physicians. These differences are statistically significant, as are the differences between physicians and nurse practitioners within the two visit periods. In walk-in visit periods, nurse practitioners' visits were 63 percent longer than were those made to physicians, and 40 percent longer than in scheduled visit periods.
This table also explores the effects of various visit characteristics on average patient care times. Whether or not laboratory and/or x-ray procedures were ordered had a sizable affect on patient care times for nurse practitioners but not for physicians. Although such procedures were usually performed the same day, direct patient care times could have been affected not by the time accounted for in obtaining the tests, but in discussions between parent and provider about them.
The difference in the allocation of support services is seen in the time patients' spent with health assistants who prepared only physicians' patients for examination. Physicians' patients spent an average of 4 minutes with a health assistant, compared to about 18 seconds for nurse practitioners' patients.
Prescriptions did not affect direct patient care times for either physicians or nurse practitioners. Even though physicians wrote all prescriptions for nurse practitioner patients, the nurse practitioners usually left their patients alone in the examination rooms while they obtained the prescriptions. Therefore, this time was not counted as direct patient care.
The differential allocation of support services to physicians and nulrse practitioners resulted in a division of labor that had important implications for the productivity analyses. Tasks that health assistants undertook for physicians--weighing patients, taking temperatures, preparing them for examination--had to be performed by nurse practitioners for their own patients. The time required for nurse practitioners to do these tasks was by definition direct patient care time, and probably accounts for some of the substantial difference between physicians and nurse practitioners in direct patient care times. These differences will be examined in more detail below.
The number of children seen simultaneously affected average patient care times for visits to physicians during walk-in visit periods, and for visits to nurse practitioners during scheduled visit periods. The number of cases in the two-or-more-patients category is relatively small, however, and the mean may be atypical. In both cases, direct patient care times were longer when two or more children were seen. Unexpectedly, the number of patients seen did not affect visits to nurse practitioners during walk-in visit periods.
Another approach to the data focuses on the providers and how they allocated their time. The denominator here is the total number of hours they were observed in the 2 week period. The percentage of their time that the providers spent in patient care was 57 percent for physicians, and 64 percent for
Analysis of Direct Patient Care Time
This table displays also average patient care times by diagnosis and by purpose of the visit. These two variables are highly intercorrelated, but they represent different aspects of the visit. Purpose was recorded on the encounter form at the outset of the visit, and described the reason for making the visit from the patient's (or parent's) point of view. As this factor would be influential in determining the amount of time set aside for the visit, it was anticipated that it would have a significant affect, as it did, on average patient care times. The table shows purpose categorized into illness and well care. There were a small number of visits that had other purposes, and since most of these were not illness-related, they were combined with the well-care visits.
To demonstrate potential applications of the observation data, factors affecting variations in direct patient care times are examined in this section. It should be noted that when two or three children were seen during the same visit, the second and
The differences between physicians and nurse practitioners for this variable is statistically significant only for illness visits in walk-inperiods, where visits to nurse practitioners averaged 10.7 minutes of direct patient care, and visits to phy-
nurse practitioners. When examined separately for walk-in and scheduled visit times, the findings are quite different. During walk-in periods, physicians spent 54 percent of their time in direct patient care, and nurse practitioners spent 58 percent. Inscheduled periods, however, 73 percent of nurse practitioners' time was spent in direct patient care, compared to 65 percent for physicians (P < .001). An explanation for these differences probably lies in the different character of demands on the non-patient care time experienced by the two types of health care professionals.
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TABLE 3:
Average
Direct Patient Care Times for Physicians and Nurse Practitioners by Characteristics of the Visit
Emergency
Scheduled
M. D.
N.P.
M.D.
N.P.
Number of Visits
148
102
65
38
Average Patient Care Time
8.8
14.3*
19.7
27.6*
8.0 10. 1
11 .9* 16.8*
20.7 19.0
21.3§
8.4 9.9
14.3 14.2
19.8 19.1
27.7 27.5
8.5
14.3* 14.3
19.2
24.1* 50.6
12.4 6.8 8.4 8.5 9.4
19.1 10.7* 10.3
19.1 0 8.5
30.5*
14.1* 14.2
22.2
25.4
8.3 20.0
10.8* 21.6
18.6 23.0
13.7 29.6
t-test for
differences
Laboratory and X-Ray No Yes
36.3*
Prescriptions No Yes
Number of Patients One Two or More
15.0
Diagnosis Well Care Sore Throat Otitis Media Upper Respiratory Conditions Other Illness
Purpose Illness Well Care
*
Difference between M.D. and N.P. significant at P
