18
THE NEED FOR PRIMARY CARE AS SEEN IN THE PERSPECTIVE OF PUBLIC HEALTH* DUNCAN W. CLARK, M.D. Professor and Chairman Department of Environmental Medicine and Community Health State University of New York Downstate Medical Center Brooklyn, N.Y.
B ECAUSE of the importance to public health of access to care, I shall give most attention to one of the two main meanings of primary care, namely, the concept of first-contact care. The other main meaning of primary care, that of basic or general care, was developed in the keynote address of this conference by Dr. David E. Rogers.I As first-contact care, primary care implies that there is a progression to secondary and tertiary levels in the process of medical care, as necessary. The very act of obtaining care presupposes that certain barriers to access have been overcome. The care itself usually involves a health assessment as the necessary first step to a choice among the symptomatic, definitive, supportive, custodial, preventive, or educational measures available; in actual practice such care is either episodic or continuing. In general, all persons can be said to be in need of primary medical care wherein the main providers are general practitioners, general internists, pediatricians, and obstetricians. An unresolved issue within the medical profession is whether secondary and tertiary providers of medical care are capable of incorporating responsibility for primary care within their highly specialized services.2 The first-contact aspect of primary care requires emphasis because much of the recent public demand for primary care, including certain legislative actions, owes its origin to problems associated with access (or entry) to medical care. In a public-health approach it is customary to measure mortality and morbidity indices in a community as a reflection of the health needs of its population. The groups with the higher indices of ill health are seen as the * Presented in a panel, What Is Primary Care? as part of the 1976 Annual Health Conference of the New York Academy of Medicine, Issues in Primary Care, held April 22 and 23, 1976.
Bull. N.Y. Acad. Med.
THE PERSPECTIVE OF PUBLIC HEALTH
19
more vulnerable and are assumed to be in greatest need of personal health services, even of programs designed specially for them. For many persons in such high-risk groups access to primary medical care poses a formidable problem. Included among the barriers to access are financial eligibility and various arrangements for payment, transportation, availability of the appropriate level of personnel and facility, quality of the patient's reception, personal interest and amenities of the care, and coordination and referral. Among prospective patients, ignorance about self-care or about the use of health services may be serious barriers. For a long time there has been wide agreement that in the United States we must work to improve access to personal health services. Especially in the last 10 years, many new programs which were stimulated by the federal government have been introduced to improve equality of access to care. Some programs aim at increasing the medical purchasing power of the elderly, the chronically sick, and the poor, as under Medicare and Medicaid. Other programs offer complete family care in a one-door, urban, neighborhood health center. Still another program entitles its clients to comprehensive, prepaid care at a health maintenance organization. Most but not all of these approaches share the common political aim of enhancing access to medical care for groups with special health needs who otherwise would face imposing barriers to care. But exactly what access means in an operational rather than a political sense, how to measure it and use it to monitor progress toward the social goal of greater equality has not been defined clearly. Access obviously means something beyond availability. In one model the concept of access has health policy itself as the starting point because the impact of such a policy must be evaluated. A health policy may aim at influencing the characteristics of the delivery system-e.g., resources and services and their organization, or at altering characteristics of the population at risk through improving insurance coverage, education, or some other factor. The result of change in either of the two processes is reflected in the utilization of the service and in the satisfaction of the clientele.3 In the literature there is increasing agreement that concepts of access should be considered in the context of whether those people actually in need of medical care receive it. So, the proof of access is in the utilization of the service. The concept also implies that members of the population at risk will use the services at rates that are proportional and appropriate to their needs.5 Several empirical, need-based indicators of access to care have been developed, including one by Taylor, Aday, and Andersen.6 In a nationwide Vol. 53, No. 1, January-February 1977
20 20
D.W. CLARK
survey of medical care costs and utilization conducted in 1970 these investigators employed a symptoms-response ratio. This index goes beyond patients' perceptions of health needs and adds the physician's judgment as to whether the use of care is medically appropriate. Few studies include both items. The index summarizes the difference between the number of reported medical visits in response to selected symptoms and the number of visits that a panel of medical experts estimated should have occurred. Twenty-two symptoms were chosen. Persons in the sample were asked if they had experienced any of the symptoms in the study year and whether a doctor was consulted. A panel of 40 physicians at the University of Chicago gave its opinion on the percentage of people in each subgroup that should have consulted a physician for each symptom, based on the benefit expected from available treatment. (Although the unreliability of physicians' judgment of medical need in the presence of certain symptoms suggests that refinement will be required in order to improve the method for future work, the authors conclude that the index is adequate for approximating the access of various subgroups to primary care.) At the very least, the findings in this study may be considered suggestive. What, then, is the character of the need for primary care in various population groups, excluding infants under one year of age? While over-all utilization conformed generally to current medical norms, there was much variation by age. Children from the ages of one to 18 had significantly more visits than the severity of their symptoms required. Young adults and elderly persons saw doctors at rates similar to those recommended by the panel of physicians. Middle-aged patients (aged 34 to 64) visited physicians for symptoms less often than they should have. Difference by sex was not large; men were only a little less apt than women to see a doctor when they needed one. Nonwhites saw a physician less often than they should, given the medical significance of their symptoms. Persons who live on farms in rural areas were much less likely to see a physician when symptoms appeared than were other inhabitants of rural districts or city dwellers. Persons below the poverty level saw a doctor less often for symptoms than they should, while those above this level visited at appropriate frequency. Those who had no doctor as a regular source of care reported substantially fewer visits than the actual need indicated, but those who had specialists as a regular source of care reported more visits than the medical experts deemed necessary. Among those who had a regular source of care, whites were much more likely to see a doctor than nonwhites. However, among those without a Bull. N.Y. Acad. Med.
THE PERSPECTIVE OF PUBLIC HEALTH
21
usual place to go, nonwhites were somewhat more likely than whites to see a
physician. These findings underscore the necessity for continuing our attack on barriers that deny or limit access to care. But the other half of the problem is excessive use of services. For example, as already stated, it was found in the study that people who had specialists as a regular source of care reported more visits than the medical expert panel deemed necessary. At this point it is useful to consider in detail the probable consequences of the excessive use of certain services by adverting to trends in health manpower associated with recent efforts to increase access to primary care through the supply route. Many spokesmen for the health profession continue to advocate a substantial increase in one or another category of the manpower supply. In this connection it is prudent to turn to the reflections and the projections cited by U. E. Reinhardt.7 It is generally agreed that part of the public pressure for primary care stems from the declining number of general practitioners and the relative fall in the number of physicians in private practice. During the past 25 years the United States has proceeded on the assumption that we have a serious shortage of physicians when in fact we had far more physicians than most nations. In this same period other leading industrial nations were demonstrating that, according to the usual indices of health, they could survive as well or better with fewer physicians, whereas we had acted on the assumption of a shortage and had invested massive governmental support in the expansion of medical education. In 1975 first-year medical students exceeded 15,000. Ten years previously the entering class numbered less than 10,000. So, at least until the year 2000, many more physicians will be entering medicine than leaving it. In 1971 we had about 160 physicians per 100,000 population. If there were to be no change in admissions beyond the size of the class that entered in 1975, the increase of new graduates trained in the United States would provide a ratio of 190 physicians per 100,000 population by the year 2000. In fact, we know that even more physicians will be trained in the United States since new medical schools are at various stages of planning, construction, or expansion. Moreover, this projection of 190 physicians per 100,000 population takes no account of foreign-trained medical graduates who will enter the United States during the period from 1971 to the year 2000. In recent years as many foreign medical graduates have been entering the United States as have been graduated from American schools, most of them coming for house-officer Vol. 53, No. 1, January-February 1977
22
22
D.W. CLARK
training and in expectation of return to their native lands. Even though the Congress may act to control the present recruitment of foreign-trained physicians brought to this country, an emerging problem is created by the rising number of foreign medical graduates who are United States citizens. At present, 5,000 United States citizens are said to be studying medicine abroad. None of these remarks is in criticism of foreign medical graduates. Indeed, without the entry of foreign medical graduates during the past 25 years, it is improbable that United States medical education would have been able to produce enough physicians to match the growth of the nation's population. Nor would we have been able to staff so many of our internship and residency programs, which are supportive of the prevailing system of hospital care and private medical practice. Still another response to the apparent shortage of United States-trained primary-care physicians or, more properly, to the maldistribution of physicians by specialty and geographic location, has been the invention of the category of new health professionals (NHPs). These include nursepractitioners, child-health associates, MEDEX, physician assistants, health associates, and others. In 1974 about 1,500 NHPs per year were completing training and entering practice under the supervision of physicians. Many worked in primary care. It is expected that the number of new NHPs will continue to increase. An additional influence on the problem of primary-care manpower is likely to come from continuing changes within the profession of nursing. In the last five years 30 states have revised their nurse-practice acts in ways that extend the role and function of nurses to authorize greater involvement with diagnosis and treatment. In some states diagnosis* appears to refer to nursing diagnosis and the recognition of health problems.8 While many nursepractitioners now assist physicians and work under their supervision, some leaders of the nursing profession are staunchly opposed to the nurse serving as a physician extender. In the future it is probable that we shall see more movement within nursing toward the role of copractitioner-as has been established in at least one demonstration practice-or even toward independent practitioner status and the provision of health care rather than medical care. We need to take a long-term view of short-term remedies. We have tried to *In New York State professional nursing practice is defined in part as ... diagnosing and treating human responses to actual and potential health problems through such services as case finding, health teaching, health counseling and provision of care supportive of life and well-being and executing medical regimens prescribed by a licensed or otherwise legally authorized physician or dentist ......
Bull. N.Y. Acad. Med.
THE PERSPECTIVE OF PUBLIC HEALTH
23
correct an alleged shortage of primary-care physicians by adding many new physicians, by importing physicians, and by creating new varieties of that standard primary-care physician when the basic problem has been maldistribution. Obviously, the track is going to get very crowded. The question is-which track? Will there be too many primary-care providers or too many subspecialists? In the long run, if we have too many health professionals will a greater fractionation of service occur? Will the temptation to justify the performance of questionable procedures increase? Will the cost to the public for primary and other forms of care continue to increase, in part from the sheer size of the several health professions to be supported? To summarize, our supply of health professionals will grow much more rapidly than our population. Any expectation that an excessive supply of physicians, operating from its own weight in the medical marketplace, will lead to a redistribution of physicians geographically and by specialty seems doomed to failure. The marketplace in health has not operated in this fashion in the past. Moreover, there are places in the United States where we already have more than 200 physicians per 100,000 population; these physicians make an adequate living under present arrangements for the purchase of medical care and they mostly do not tend to redistribute themselves into areas of shortage. Consider, too, that in one study of six comprehensive prepaid group practices, a mean of 109 physicians per 100,000 population was found to be needed, of whom 62/100,000 were primary-care physicians.4 In the future a burgeoning medical technology can be anticipated to continue to set the pace for our need of specialized personnel and equipment. The public will ask again and again whether marginal improvements in health and in relief of suffering are at all commensurate with the increased investment being sought. For, regrettably, the social price paid for the high cost of medical care causes underinvestment in other sectors that support and improve the public
welfare. Finally, from the perspective of public health, we need a renewed commitment to the doctrine of prevention. Perhaps we need a more extended concept of prevention, to include not only our investment in the primary prevention of disease and in clinical preventive medicine; in addition, we should prevent the inappropriate use of medical services. CONCLUSION
We can visualize the problem of primary care as mainly a need either for Vol. 53, No. 1, January-February 1977
24
D.W. CLARK
more generalists or for better access to care. I choose the latter. In our efforts to solve the problem, the easy approach of increasing the several lines of supply, with little or no public effort at coordination, can be expected ultimately to produce an excessive supply of providers of nearly every kind and undue utilization of medical resources. It will be more useful to undertake the redistribution of providers of care and the promotion of measures that assure appropriate use of health services. REFER E NCES
1. 2.
3.
4. 5.
Rodgers, D. E.: Primary care: Some issues. Bull. N.Y. Acad. Med. 53: 1977. Rubin, A. L., David, D. S., and Stenzal, K. H.: Sounding board-Effective primary care by the subspecialty center. N. Engl. J. Med. 293: 607, 1975. Aday, L. A. and Andersen, R.: Development of Indices of Access to Medical Care. Ann Arbor, Mich., Health Admin. Press, 1975. Donabedian, A.: Aspects of Medical Care Administration. Cambridge, Mass., Harvard University Press, 1973. Freeborn, D. K. and Greenlick, M. R.:
6.
7.
8.
Evaluation of the performance of ambulatory care systems. Research requirements and opportunities. Med. Care (Suppl.) 11: 68, 1973. Taylor, D. G., Aday, L. A., and Andersen, R.: A social indicator of access to medical care. J. Health Soc. Behav. 16: 39, 1975. Reinhardt, U. E.: Physician Productivity and the Demand for Health Manpower: An Economic Analysis. Cambridge, Mass., Bellinger, 1975. Bullough, B.: The law and the expanding nurse role. Am. J. Public Health 66: 249, 1976.
Bull. N.Y. Acad. Med.
THE NEED FOR PRIMARY CARE AS SEEN IN THE PERSPECTIVE OF PUBLIC HEALTH* DUNCAN W. CLARK, M.D. Professor and Chairman Department of Environmental Medicine and Community Health State University of New York Downstate Medical Center Brooklyn, N.Y.
B ECAUSE of the importance to public health of access to care, I shall give most attention to one of the two main meanings of primary care, namely, the concept of first-contact care. The other main meaning of primary care, that of basic or general care, was developed in the keynote address of this conference by Dr. David E. Rogers.I As first-contact care, primary care implies that there is a progression to secondary and tertiary levels in the process of medical care, as necessary. The very act of obtaining care presupposes that certain barriers to access have been overcome. The care itself usually involves a health assessment as the necessary first step to a choice among the symptomatic, definitive, supportive, custodial, preventive, or educational measures available; in actual practice such care is either episodic or continuing. In general, all persons can be said to be in need of primary medical care wherein the main providers are general practitioners, general internists, pediatricians, and obstetricians. An unresolved issue within the medical profession is whether secondary and tertiary providers of medical care are capable of incorporating responsibility for primary care within their highly specialized services.2 The first-contact aspect of primary care requires emphasis because much of the recent public demand for primary care, including certain legislative actions, owes its origin to problems associated with access (or entry) to medical care. In a public-health approach it is customary to measure mortality and morbidity indices in a community as a reflection of the health needs of its population. The groups with the higher indices of ill health are seen as the * Presented in a panel, What Is Primary Care? as part of the 1976 Annual Health Conference of the New York Academy of Medicine, Issues in Primary Care, held April 22 and 23, 1976.
Bull. N.Y. Acad. Med.
THE PERSPECTIVE OF PUBLIC HEALTH
19
more vulnerable and are assumed to be in greatest need of personal health services, even of programs designed specially for them. For many persons in such high-risk groups access to primary medical care poses a formidable problem. Included among the barriers to access are financial eligibility and various arrangements for payment, transportation, availability of the appropriate level of personnel and facility, quality of the patient's reception, personal interest and amenities of the care, and coordination and referral. Among prospective patients, ignorance about self-care or about the use of health services may be serious barriers. For a long time there has been wide agreement that in the United States we must work to improve access to personal health services. Especially in the last 10 years, many new programs which were stimulated by the federal government have been introduced to improve equality of access to care. Some programs aim at increasing the medical purchasing power of the elderly, the chronically sick, and the poor, as under Medicare and Medicaid. Other programs offer complete family care in a one-door, urban, neighborhood health center. Still another program entitles its clients to comprehensive, prepaid care at a health maintenance organization. Most but not all of these approaches share the common political aim of enhancing access to medical care for groups with special health needs who otherwise would face imposing barriers to care. But exactly what access means in an operational rather than a political sense, how to measure it and use it to monitor progress toward the social goal of greater equality has not been defined clearly. Access obviously means something beyond availability. In one model the concept of access has health policy itself as the starting point because the impact of such a policy must be evaluated. A health policy may aim at influencing the characteristics of the delivery system-e.g., resources and services and their organization, or at altering characteristics of the population at risk through improving insurance coverage, education, or some other factor. The result of change in either of the two processes is reflected in the utilization of the service and in the satisfaction of the clientele.3 In the literature there is increasing agreement that concepts of access should be considered in the context of whether those people actually in need of medical care receive it. So, the proof of access is in the utilization of the service. The concept also implies that members of the population at risk will use the services at rates that are proportional and appropriate to their needs.5 Several empirical, need-based indicators of access to care have been developed, including one by Taylor, Aday, and Andersen.6 In a nationwide Vol. 53, No. 1, January-February 1977
20 20
D.W. CLARK
survey of medical care costs and utilization conducted in 1970 these investigators employed a symptoms-response ratio. This index goes beyond patients' perceptions of health needs and adds the physician's judgment as to whether the use of care is medically appropriate. Few studies include both items. The index summarizes the difference between the number of reported medical visits in response to selected symptoms and the number of visits that a panel of medical experts estimated should have occurred. Twenty-two symptoms were chosen. Persons in the sample were asked if they had experienced any of the symptoms in the study year and whether a doctor was consulted. A panel of 40 physicians at the University of Chicago gave its opinion on the percentage of people in each subgroup that should have consulted a physician for each symptom, based on the benefit expected from available treatment. (Although the unreliability of physicians' judgment of medical need in the presence of certain symptoms suggests that refinement will be required in order to improve the method for future work, the authors conclude that the index is adequate for approximating the access of various subgroups to primary care.) At the very least, the findings in this study may be considered suggestive. What, then, is the character of the need for primary care in various population groups, excluding infants under one year of age? While over-all utilization conformed generally to current medical norms, there was much variation by age. Children from the ages of one to 18 had significantly more visits than the severity of their symptoms required. Young adults and elderly persons saw doctors at rates similar to those recommended by the panel of physicians. Middle-aged patients (aged 34 to 64) visited physicians for symptoms less often than they should have. Difference by sex was not large; men were only a little less apt than women to see a doctor when they needed one. Nonwhites saw a physician less often than they should, given the medical significance of their symptoms. Persons who live on farms in rural areas were much less likely to see a physician when symptoms appeared than were other inhabitants of rural districts or city dwellers. Persons below the poverty level saw a doctor less often for symptoms than they should, while those above this level visited at appropriate frequency. Those who had no doctor as a regular source of care reported substantially fewer visits than the actual need indicated, but those who had specialists as a regular source of care reported more visits than the medical experts deemed necessary. Among those who had a regular source of care, whites were much more likely to see a doctor than nonwhites. However, among those without a Bull. N.Y. Acad. Med.
THE PERSPECTIVE OF PUBLIC HEALTH
21
usual place to go, nonwhites were somewhat more likely than whites to see a
physician. These findings underscore the necessity for continuing our attack on barriers that deny or limit access to care. But the other half of the problem is excessive use of services. For example, as already stated, it was found in the study that people who had specialists as a regular source of care reported more visits than the medical expert panel deemed necessary. At this point it is useful to consider in detail the probable consequences of the excessive use of certain services by adverting to trends in health manpower associated with recent efforts to increase access to primary care through the supply route. Many spokesmen for the health profession continue to advocate a substantial increase in one or another category of the manpower supply. In this connection it is prudent to turn to the reflections and the projections cited by U. E. Reinhardt.7 It is generally agreed that part of the public pressure for primary care stems from the declining number of general practitioners and the relative fall in the number of physicians in private practice. During the past 25 years the United States has proceeded on the assumption that we have a serious shortage of physicians when in fact we had far more physicians than most nations. In this same period other leading industrial nations were demonstrating that, according to the usual indices of health, they could survive as well or better with fewer physicians, whereas we had acted on the assumption of a shortage and had invested massive governmental support in the expansion of medical education. In 1975 first-year medical students exceeded 15,000. Ten years previously the entering class numbered less than 10,000. So, at least until the year 2000, many more physicians will be entering medicine than leaving it. In 1971 we had about 160 physicians per 100,000 population. If there were to be no change in admissions beyond the size of the class that entered in 1975, the increase of new graduates trained in the United States would provide a ratio of 190 physicians per 100,000 population by the year 2000. In fact, we know that even more physicians will be trained in the United States since new medical schools are at various stages of planning, construction, or expansion. Moreover, this projection of 190 physicians per 100,000 population takes no account of foreign-trained medical graduates who will enter the United States during the period from 1971 to the year 2000. In recent years as many foreign medical graduates have been entering the United States as have been graduated from American schools, most of them coming for house-officer Vol. 53, No. 1, January-February 1977
22
22
D.W. CLARK
training and in expectation of return to their native lands. Even though the Congress may act to control the present recruitment of foreign-trained physicians brought to this country, an emerging problem is created by the rising number of foreign medical graduates who are United States citizens. At present, 5,000 United States citizens are said to be studying medicine abroad. None of these remarks is in criticism of foreign medical graduates. Indeed, without the entry of foreign medical graduates during the past 25 years, it is improbable that United States medical education would have been able to produce enough physicians to match the growth of the nation's population. Nor would we have been able to staff so many of our internship and residency programs, which are supportive of the prevailing system of hospital care and private medical practice. Still another response to the apparent shortage of United States-trained primary-care physicians or, more properly, to the maldistribution of physicians by specialty and geographic location, has been the invention of the category of new health professionals (NHPs). These include nursepractitioners, child-health associates, MEDEX, physician assistants, health associates, and others. In 1974 about 1,500 NHPs per year were completing training and entering practice under the supervision of physicians. Many worked in primary care. It is expected that the number of new NHPs will continue to increase. An additional influence on the problem of primary-care manpower is likely to come from continuing changes within the profession of nursing. In the last five years 30 states have revised their nurse-practice acts in ways that extend the role and function of nurses to authorize greater involvement with diagnosis and treatment. In some states diagnosis* appears to refer to nursing diagnosis and the recognition of health problems.8 While many nursepractitioners now assist physicians and work under their supervision, some leaders of the nursing profession are staunchly opposed to the nurse serving as a physician extender. In the future it is probable that we shall see more movement within nursing toward the role of copractitioner-as has been established in at least one demonstration practice-or even toward independent practitioner status and the provision of health care rather than medical care. We need to take a long-term view of short-term remedies. We have tried to *In New York State professional nursing practice is defined in part as ... diagnosing and treating human responses to actual and potential health problems through such services as case finding, health teaching, health counseling and provision of care supportive of life and well-being and executing medical regimens prescribed by a licensed or otherwise legally authorized physician or dentist ......
Bull. N.Y. Acad. Med.
THE PERSPECTIVE OF PUBLIC HEALTH
23
correct an alleged shortage of primary-care physicians by adding many new physicians, by importing physicians, and by creating new varieties of that standard primary-care physician when the basic problem has been maldistribution. Obviously, the track is going to get very crowded. The question is-which track? Will there be too many primary-care providers or too many subspecialists? In the long run, if we have too many health professionals will a greater fractionation of service occur? Will the temptation to justify the performance of questionable procedures increase? Will the cost to the public for primary and other forms of care continue to increase, in part from the sheer size of the several health professions to be supported? To summarize, our supply of health professionals will grow much more rapidly than our population. Any expectation that an excessive supply of physicians, operating from its own weight in the medical marketplace, will lead to a redistribution of physicians geographically and by specialty seems doomed to failure. The marketplace in health has not operated in this fashion in the past. Moreover, there are places in the United States where we already have more than 200 physicians per 100,000 population; these physicians make an adequate living under present arrangements for the purchase of medical care and they mostly do not tend to redistribute themselves into areas of shortage. Consider, too, that in one study of six comprehensive prepaid group practices, a mean of 109 physicians per 100,000 population was found to be needed, of whom 62/100,000 were primary-care physicians.4 In the future a burgeoning medical technology can be anticipated to continue to set the pace for our need of specialized personnel and equipment. The public will ask again and again whether marginal improvements in health and in relief of suffering are at all commensurate with the increased investment being sought. For, regrettably, the social price paid for the high cost of medical care causes underinvestment in other sectors that support and improve the public
welfare. Finally, from the perspective of public health, we need a renewed commitment to the doctrine of prevention. Perhaps we need a more extended concept of prevention, to include not only our investment in the primary prevention of disease and in clinical preventive medicine; in addition, we should prevent the inappropriate use of medical services. CONCLUSION
We can visualize the problem of primary care as mainly a need either for Vol. 53, No. 1, January-February 1977
24
D.W. CLARK
more generalists or for better access to care. I choose the latter. In our efforts to solve the problem, the easy approach of increasing the several lines of supply, with little or no public effort at coordination, can be expected ultimately to produce an excessive supply of providers of nearly every kind and undue utilization of medical resources. It will be more useful to undertake the redistribution of providers of care and the promotion of measures that assure appropriate use of health services. REFER E NCES
1. 2.
3.
4. 5.
Rodgers, D. E.: Primary care: Some issues. Bull. N.Y. Acad. Med. 53: 1977. Rubin, A. L., David, D. S., and Stenzal, K. H.: Sounding board-Effective primary care by the subspecialty center. N. Engl. J. Med. 293: 607, 1975. Aday, L. A. and Andersen, R.: Development of Indices of Access to Medical Care. Ann Arbor, Mich., Health Admin. Press, 1975. Donabedian, A.: Aspects of Medical Care Administration. Cambridge, Mass., Harvard University Press, 1973. Freeborn, D. K. and Greenlick, M. R.:
6.
7.
8.
Evaluation of the performance of ambulatory care systems. Research requirements and opportunities. Med. Care (Suppl.) 11: 68, 1973. Taylor, D. G., Aday, L. A., and Andersen, R.: A social indicator of access to medical care. J. Health Soc. Behav. 16: 39, 1975. Reinhardt, U. E.: Physician Productivity and the Demand for Health Manpower: An Economic Analysis. Cambridge, Mass., Bellinger, 1975. Bullough, B.: The law and the expanding nurse role. Am. J. Public Health 66: 249, 1976.
Bull. N.Y. Acad. Med.
