Sharon K. Gershon, R.Ph., Safety Evaluator, Office of Biostatistics and Epidemiology, Center for Biologics Evaluation and Research, Food and Drug Administration, Rockville, MD
James M. Cultice, B.S., Technical Director for Modeling and Research, National Center for Health Workforce and Analysis, Bureau of Health Professions, Health Resources and Services Administration (HRSA), USDHHS, Rockville, MD
Katherine Knapp, Ph.D., Professor and Associate Dean, University of the Pacific School of Pharmacy and Health Sciences, Stockton, CA
For reprint requests: Sharon K. Gershon, R.Ph., 1401 Rockville Pike, WOC I, 200 S, HFM-224, Rockville, MD 20852
Presented at the Annual Meeting, American Society of Health-System Pharmacists, Philadelphia, PA, June 5, 2000.
Acknowledgements. The authors wish to acknowledge RADM Fred Paavola, Chief Pharmacy Officer, U.S. Public Health Service, Bureau of Health Professions, Health Resources and Services Administration (HRSA) and Stuart Bernstein, Health Statistician, Bureau of Health Professions, National Center for Health Workforce Information and Analysis, HRSA, for their valued support and assistance on this project.
ABSTRACT
Objective. To describe a Bureau of Health Professions model for estimating active pharmacists in the United States and its findings.
Methods. We constructed a model using as base counts data from the Pharmacy Manpower Project census of 1989 to 1991 and advancing the counts annually based on estimates of those entering and leaving the workforce. The total of active pharmacists in any year was the sum of the male and female cohorts from age 24 to age 75. The model and its underlying assumptions included consideration of U.S. graduates through 1998, international pharmacy graduates achieving licensure in the U.S., new schools, type of entry-level degrees and separation rates. A Basic Series and high and low alternatives were constructed based on different assumptions.
Main Results. The Basic Series projected 196,011 active pharmacists in 2000, 224,524 by 2010 and 249,086 by 2020. Estimated pharmacists per 100,000-population were 71.2 in 2000, 74.9 in 2010, and 76.7 in 2020. The workforce was projected to be increasingly female: 32% in 1991, 46% in 2000, 50% in 2003, and 64% in 2020. Percentages of graduates receiving the BS degree fell from 94% (1980) to 64.4% (1998) and were projected to decrease to 0% by 2005. Estimated U.S. graduates were 7,945 in 2000, 8,133 in 2010 and 8,452 in 2020. The mean age in 2000 was 38 years for women pharmacists, 46 for men and 42 overall. Estimates of total pharmacists in 1998 were similar to those from other sources increasing confidence in the model.
Conclusions. The model, which is readily revisable as more and better data become available, provided estimates of active pharmacists by age and gender from 1991 to 2020. The model portrayed an increasingly female pharmacy workforce with more pharmacists holding the PharmD degree. The model and data are useful for research, analysis and healthcare planning.
INTRODUCTION
Today there is growing apprehension and mounting evidence in the pharmacy community and among healthcare policymakers that the future pharmacist supply may not be adequate to meet the nation's needs for pharmaceutical services.1,2 The sharp increase in vacancies and the inability to fill positions, the rapid growth in prescription volume, the increase in new drugs and their greater complexities, and the growth in the elderly population are all indicators of a rapid and persistent rise in demand for pharmacists. In addition, the national focus on medication errors, some attributable to inadequate pharmacist staffing and job stress have drawn attention to the need for an adequate supply of pharmacists.
Concern about the adequacy of the supply of pharmacists in the United States is not a new issue. Particularly during periods of shortage, studies addressing the demography and work patterns of pharmacists have appeared.3,4,5,6,7,8,9,10 These efforts and their ability to explain events such as periodic shortages have been hampered by the scarcity of basic data about the size and characteristics of the pharmacy workforce. Today pharmacists represent the third largest health professional group in the United States and yet pharmacy has lagged behind other health professions in the area of data collection. For example, the American Medical Association, the American Dental Association and the American Academy of Physician Assistants maintain and update comprehensive national databases that provide detailed demographic and geographic information about their professions' composition. Parallel data do not exist about pharmacists.Lacking a current comprehensive database, pharmacist workforce studies have relied on surveys based on samples, census surveys and modeling. The last national census count of pharmacists was completed in the early 1990s11 and does not account for more recent events such as the opening of new schools, recent enrollment trends, transitioning to the Doctor of Pharmacy (PharmD) entry-level degree or the continuing rise in women pharmacists. Over the last two years, the Bureau of Health Professions (BHPr), which has historically created and maintained models for healthcare workers, constructed a pharmacist supply model and applied it to generate new estimates of pharmacist numbers and characteristics in the United States through 2020. The model includes a basic series and high and low alternative series based on alternative assumptions about new entrants into the workforce. The purpose of this paper is to describe the BHPr Pharmacist Supply Model and relate its findings. We provide projections of the supply of active pharmacists under different scenarios using the latest available data on enrollment and graduate trends and assumptions about losses from the supply pool. Also presented are estimates of the age distribution of the workforce in 2000, the percent PharmD graduates and the gender balance of the workforce. It is expected that the data generated by the model will provide an authoritative source of baseline and predictive data about pharmacists. The data should be useful to a wide range of persons and organizations including health planners at Federal, State and local levels, managed care organizations, health researchers, pharmacy educators, professional associations and employers of pharmacists in the community, institutional and other sectors of the pharmacy industry, all of whom depend on the availability of pharmacists and pharmaceutical services.
METHODS
Structure of the Model.
The pharmacist supply model is based on a year-by-year progression of cohorts of age and gender-based pharmacists. The total number of pharmacists in any given year is the sum of the male and female pharmacists from 1-year age group cohorts starting at age 24 and extending to age 75. The BHPr Pharmacist Supply Model operates essentially as follows: it takes base-year counts of active pharmacists, extracted the Pharmacy Manpower Project (PMP) census database11, then projects those numbers forward in time by (i) adding, each year, the projected number of new entrants and (ii) subtracting, each year, the projected number of both base year pharmacists and post 1991 new entrants who will die or retire. At any point in time, the composite of base year pharmacists and new entrants who have neither died nor retired constitutes the active pharmacist supply. The process is repeated iteratively from base year 1991 through 2020, the end of the forecast period.
The data for each of the base cohorts were drawn from the 1989-1991 PMP census project; we identify 1991 as the base year for the model. The historic data for new graduates were drawn from the American Association of Colleges of Pharmacy (AACP) annual reports on enrollments and graduates. The number of survivors in each gender and age-based cohort throughout the projection period was estimated by application of a separation rate that computes the percentage of a particular cohort leaving the workforce in the following year.
Estimates of New Graduates and New Schools
We obtained data on historic graduates by gender and entry-level degree (Bachelor of Science or Doctor of Pharmacy) from 1991 through 1998 from the American Association of Colleges of Pharmacy (AACP). In order to estimate new graduates from 1999 to 2020, we reviewed three variables that could influence future enrollments. First, eight new schools were founded between 1980 and 2000 and we anticipated that additional schools would be opened through 2020. Second, applications to pharmacy programs have been fluctuating. They increased during the first half of the 1990s and decreased during the second half. Therefore, at a time when the number of places in pharmacy programs was increasing, the number of applicants was decreasing. Insufficient applicants could render the opening of new schools not feasible. Finally, we considered the transition to the entry-level Doctor of Pharmacy (PharmD) program. Of the 81 schools of pharmacy, all but eleven made the transition to the PharmD degree during the 1990s. For those schools still in transition, we needed to know whether the conversion would result in changes in graduate numbers. Telephone inquiries were directed to the 15 schools still in transition. Nine schools indicated their intent to at least maintain current enrollments. Planned decreases among the remaining schools ranged from 9% to 20%.
Based on the information gathered from the inquiries, we assumed that all current schools would continue to exist and that each new school would eventually add 90 graduates per year, the average value for existing schools. For the Basic Series, we assumed that three schools would be added between 2000 and 2010 and three more schools between 2010 and 2020. We chose this rate, which was slightly lower than the rate of new school formation over the past 20 years, because of the continuing decline of the applicant pool that could interfere with the feasibility of new schools. For the Low Series, we assumed that no schools would be added after 2000; and for the High Series, we assumed that one new school would be added every other year throughout the projection period, a rate higher than the historical average over the past 20 years.
International Pharmacy Graduates
The supply of most health professions in the United States is augmented to some extent by the addition of graduates from other countries who become licensed to practice in the United States. Historically, IPGs have not entered practice in the United States in large numbers. For example, an earlier report estimated that approximately 200 IPGs per year were licensed to practice pharmacy in the middle 1980s.12 Nevertheless, we felt it was appropriate to include a variable for international pharmacy graduates (IPGs) in the model and we investigated the status of IPGs in the workforce.
We contacted the National Association of Boards of Pharmacy (NABP) to obtain data on the number of IPGs who had passed the National Association of Boards of Pharmacy Licensing Examination (NABPLEX) since 1990; these data indicated that between 1997 and 1999, there were 163, 266 and 358 IPGs licensed respectively. Opposing this upward trend, NABP has declared that in 2003 when the requirement for an entry-level PharmD degree is enforced nationally, IPGs will be eligible to attempt the NAPLEX only if they hold a 5-year pharmacy degree. Since most pharmacy programs outside the United States are 4-year programs, this change in NABP policy is likely to reduce IPG entrants into U.S. practice, although some pharmacy schools find it attractive to develop programs addressing this deficit.
Because California has its own licensing process, we contacted the California State Board of Pharmacy for similar information. Their data showed that between 1997 and 1999, there were 52, 56 and 51 IPGs licensed respectively. Additionally, data on California pass rates showed that IPGs had consistently low pass rates suggesting that many IPGs took the examination more than once prior to passing. In 1998, the California State Board of Pharmacy voted to require any candidate who had failed the examination four times or more to complete a substantial amount of graded coursework at an accredited school of pharmacy in the regular pharmacy curriculum before attempting the examination again. The opportunities for enrollment in coursework meeting the Board's requirements have been very limited and thus we assumed that future numbers of IPG pharmacists entering practice in California will remain at current levels. Again, the possibility exists that schools could decide to offer programs meeting the Board's requirements.
Based on these limited data, we estimated 314 annual additions to the pharmacy workforce due to IPGs for the basic series of the revised model. This value represents the mean of total IPGs each year from 1997-1999. For the Low and High Series, we subtracted or added 97 IPGs which represents the value of one standard deviation from the mean value of 314. Thus, for the Low Series, we used a constant value of 217 IPGs each year, and for the High Series, 411 IPGs each year.
Separation Rates
Separation rate tables are an essential tool for modeling departure from the workforce over time. The rates, which are usually based on actuarial estimates of retirement, death and sometimes occupational mobility (changing one's type of job), typically describe the percent of an age- and gender-based cohort that will leave the workforce in a given time period. As an example, a one-year separation rate of 0.005 for a cohort of 30-year old women pharmacists would be used to calculate that 99.5% of the 30-year cohort of women pharmacists would remain in the workforce as 31-year olds.
Compiling reliable separation rates for the range of working years (generally the early 20s to over 75 years of age) requires large amounts of data leading to a scarcity of rate tables specific for a given occupation or a given point in time. Lacking a separation rate table specific for pharmacists, an earlier study applied different rate tables, including one for physicians and another for clerical workers, to a model of pharmacists divided into age- and gender-based cohorts.13 This study showed that application of the different tables resulted in vastly different supply estimates over time. Since a rate table specific for pharmacists still does not exist, we reviewed the available rate tables and tested several sets of rates to see which set was the best predictor. The test involved systematically applying different rate sets to project the 1978 base count of active pharmacists to 1991 and comparing the results to the base counts of the PMP census.11 We judged this test to show the extent to which different separation rate tables matched the workforce participation behavior of pharmacists during the 1980s. Based on this analysis, we chose to use the 1988 civilian labor force separation rates from the Bureau of Labor Statistics (BLS). This dataset consisted of separation rates by gender for 5-year age-based cohorts. The rates are presented in Table 1. Applying these rates and the differing assumptions about graduate entrants, we developed the Low Series, a Basic Series and a High Series that estimates pharmacy graduates and pharmacist numbers by gender and age from 1991 through 2020.
Table 1. Bureau of Labor Statistics Civilian Separation Rates by Age and Gender, 1988
RESULTS
Table 2 describes the pharmacist estimates derived from the BHPr Pharmacist Supply Model. All estimates described here are drawn from the Basic Series unless otherwise specified. The model projects 196,011 active pharmacists for 2000. The supply of active pharmacists is projected to reach 224,524 by 2010 and 249,086 by 2020, a 45 % increase over 1991 PMP census estimate of 171,611, an annual growth rate of 1.3%. In the alternative estimates, total supply is projected to range from 221,823 (Low Series) to 226,791 (High Series) in 2010, a difference of 2.2%. By 2020, the alternative projections range from 242,034 (Low Series) to 253,919 (High Series), a difference of 4.7%.
Table 2. Pharmacy Supply Model Results 1991-2020: Total Active Pharmacists by Year, Graduates, International Pharmacy Graduates Licensed in the U.S. and Workforce Loss Due to Death and Retirement.
Table 3 describes the ratio of pharmacists per 100,000 population from 1995 through 2020. The supply is expected to expand at a slightly higher rate than the general population. Currently (2000) we estimated about 71.2 pharmacists per 100,000 population. The ratio is expected to rise to about 74.9 per 100,000 persons in 2010, and reach 76.7 per 100,000 in 2020. The alternative series projects the pharmacist to population ratio to range between 74 (Low Series) to 75.6 pharmacists (High Series) per 100,000 in 2010, and 74.5 (Low Series) to 78.1 pharmacists (High Series) in 2020. These results indicate that even with no new schools or expansion of existing schools during the projection period, growth in the supply will still outpace population growth which is about 1.01% annually.
Table 3. Ratios of Active Pharmacists to 100,000-Population: 1995-2020
Figure 1 describes the gender distribution of the workforce from 1991 through 2020. Women accounted for about 32% of pharmacists in 1991. Since then, increases in female first year enrollments in pharmacy schools have resulted in substantial growth in numbers of women pharmacists in all positions. Also contributing to the increasingly female workforce is the projection that pharmacists leaving the workforce will be predominantly male. Currently 46% of the pharmacist supply are estimated to be women. By 2003, about 50% of active pharmacists are expected to be women. By 2020, men are expected to be only 36% of total supply.
Figure 1. Pharmacists by gender: projected 1995-2020.
Figure 2 describes the estimated age distribution of active pharmacists in 2000 by gender. The curve is not "smooth" because we used five-year separation rates instead of one-year rates. The "upturn" at age 75 is an artifact reflecting pharmacists remaining in the model at age 75, the last cohort. Because of this distortion, the values at age 75 were not used in calculating the mean or median ages. The mean and median ages for men pharmacists were both 46 years, for women pharmacists were 38 and 35 years and for all pharmacists were 42 and 40 years respectively.
Figure 2. U.S. pharmacy graduates: 1980-2020.
Figure 3 describes a combination of historical and projected estimates of total graduates from 1980 to 2020. Percentages of graduates receiving the BS degree decreased from 94% (1980) to 86.4% (1990) to 64.4% (1998). Graduate numbers, which decreased more than 20% in the 1980s, rebounded in the 1990s rising to a high value of 8,003 in 1996 and decreased again through 1998. The decreased numbers of graduates during the 1980s are reflected in the base-counts for our model and continue to exert a downward impact on the overall supply.
Figure 3. Age Distribution of Active Pharmacists by Gender and Overall, 2000
Figure 4 describes estimates of graduates and the distribution of entry-level degrees, Bachelor of Science or Doctor of Pharmacy, from 1991 through 2006. After 2005, it was assumed that all U.S. graduates would obtain the PharmD degree. After 2003, the alternate series diverged based on differing assumptions about new schools. U.S. graduates are projected to number 7,945 in 2000, 8,133 in 2010 and 8,452 in 2020 in the Basic Series. Estimated graduates in the Low Series are 7,943 in both 2010 and 2020. Estimates for the High Series are 8,293 in 2010 and 8,692 in 2020. The Low Series shows 509 fewer graduates in 2020 that the Basic Series while the High Series has 240 more graduates than the Basic Series. We did not estimate the percentage of the overall workforce holding each degree for the projection years.
Figure 4. U.S. Pharmacy Graduates: 1980-1998, Projected from 1999 to 2020.
DISCUSSION
As a test of the model's validity in estimating pharmacist numbers, we investigated other estimates of pharmacist numbers and pharmacy positions. We compared the 1997 to 1999 estimates of total active pharmacists in our model to those reported by Bureau of Labor Statistics (BLS) and Census Bureau, recognizing that generally Census Bureau data are based on counts of people while BLS data are based on positions. The values in the BHPr model for these three years were 187,067, 189,697 and 192,793 active pharmacists respectively. Current Population Survey (CPS) data collected by the Census Bureau reported 200,000 pharmacists in 1997 with 195,000 counted as "wage and salary workers" and 5,000 counted as self-employed workers.a For 1998, the Census Bureau reported 180,000 pharmacists with 173,000 counted as "wage and salary workers" and 6,000 as self-employed workers. The corresponding figure for 1999 was 216,000 pharmacists with 204,000 reported as employees and 11,000 as self-employed workers.a The wide variation in CPS data for the three years was due to the relatively small number of pharmacists sampled, with values falling above and below the Bureau of Health Professions estimates.
A second comparison was made with data from the revised BLS 1998 National Occupational Employment and Wage Estimates. This source reported the number of pharmacists as 174,540 for 1997 and 178,110 for 1998. Data for 1999 were not available. These data were collected from employers and did not include self-employed pharmacists; if self-employed pharmacist estimates from CPS are added, these totals approximated those in our model. Corroborating data also came from the BLS National Industry-Occupation Employment Matrix from 1998, which reported a total of 185,324 pharmacists according to their place of employment. Finally, in a separate report, BLS Occupational Employment Statistics reported a total of 177,350 employed pharmacists in 1998. All the reports, after adjustment to include self-employed pharmacists, suggested that the totals calculated in the BHPr Pharmacist Supply Model were reasonably representative of the United States active pharmacy work force.
Validation of the total pharmacist numbers through 1998 allowed us to draw conclusions about the validity of other aspects of the model. In creating the model, we made assumptions about numbers of U.S. graduates and IPGs, numbers of schools and an appropriate set of separation rates. For the years 1991 through 1998, detailed data about graduates and schools were available, as were limited data about IPGs. With these values known, the predictive capacity of the model through 1998 became a measure of the validity of the separation rates we selected and, to a lesser extent, estimates of IPGs. The agreement between the model totals and counts from other sources increased our confidence about the choice of separation rates and IPG estimates.
A slowly increasing pharmacist-to-population ratio was estimated for years 1991 through 2020 yet we know the historic period to have been marked by fluctuations in the supply-to-demand balance in the marketplace. This finding suggests this single measure is not sufficient for judging the adequacy of the pharmacist supply. To explain events such as the current shortage of pharmacists requires exploration of multiple factors extending beyond supply issues including, for example, the aging of the population, the growth of prescription drug benefits, the growth of prescriptions and changing roles of pharmacists. Although that task is beyond the scope of this paper, for that larger consideration, the results from our study will be helpful in addressing supply-related issues.
We compared the model's age distribution in 2000 to the age distribution described by the 1991 PMP census data11. The mean age for the PMP census was 44.4 years with the mean for women 37.5 years and for men 47.6. While the gender-based means were very similar, the change in the gender ratio since 1991 decreased the model's mean age by more than two years. Thus, the overall workforce has become slightly younger in the last decade. We also noted that the model's mean age of 42 years in 2000 was similar across several more recent studies. For example, a 1995 analysis of 1,637 pharmacist surveys found a mean age of 43 years7; and a 2000 analysis of 2,092 surveys found mean age of 42.6 years for active pharmacists working full-time and 48.6 years for part-time pharmacists14.
The introduction of IPGs into the model made the model more representative of the pharmacy work force. Nevertheless, with so few data available and such uncertainty about the future for IPG licensure in the U.S., it was difficult to justify predicting either increases or decreases in future IPG workforce entrants. Although we addressed this dilemma by using constants for the three series, this could be seen as a temporary measure. As the questions currently surrounding the future of IPGs in the U.S. workforce are answered, the model should be adjusted to reflect the extent of IPG licensure. The ability to make adjustments easily is a distinct value of the model.
Predicting graduates in the model was highly dependent on estimating the number and size of pharmacy schools in the future. The telephone inquiry allowed us to estimate the near future impact of changes such as the movement to the universal entry-level Doctor of Pharmacy degree. For the longer term, we noted that continuing declines in the applicant pools and the recent surge in new schools presented another dilemma in terms of opposing trends. Our assumption of adding one new school every three years in the Basic Series was a conservative choice given recent history and may therefore underestimate supply. The possible underestimation is balanced by assuming entering classes of 100 students in new schools while several of the recently opened schools have offered only 75 to 80 seats. As with IPGs, should future developments render the assumptions about new schools invalid, the model will need to be adjusted.
Whatever the number of new graduates, the fact that all new graduates will hold the Doctor of Pharmacy degree after 2003 is likely to impact the workforce as it faces the challenges of new roles in healthcare. For example, pharmacists are contributing to public health initiatives such as immunization and smoking cessation programs, working in the managed care environment in disease state management programs and as pharmacy benefit planners and managers as well as expanding responsibility for the direct care of patients in clinic settings. 15With national implementation of the PharmD requirement, new pharmacists entering the work force will have completed more advanced college course work prior to entering the professional program and will bring new knowledge and skills to the work place. For many new roles, the additional maturity and preparation of future graduates will influence the image and utility of the pharmacist work force. On a more mundane note, the end of the PharmD transition will mark a period of more certainty about graduate numbers.
The model shows a workforce becoming increasingly female during the early twenty-first century. It is important to remember that the model represents a count of active pharmacists and does not reflect the level of participation in the work force. Many studies have shown that more women pharmacists work less than full-time than men pharmacists.3,4,7,14 Therefore, the headcounts produced by our model almost certainly underestimate the full-time equivalent (FTE) size of the workforce. A calculation of the difference is beyond the scope of this paper; however, a better understanding of the relationship between the model's "headcount" estimates and the FTE count of pharmacists is an important research endeavor that should have high priority.
Limitations.
The BHPr Pharmacist Supply Model is being revised to convert headcounts to FTE measures, but its current inability to do so represents a limitation of the model. Other limitations related to our lack of knowledge about IPG trends and new schools have already been noted. Another notable gap in the data produced by the model is the lack of a geographic component. Most of the pharmacy manpower problems that have developed over the past 15 years have had a regional character. The data provided by the model do not improve our understanding of the national distribution of pharmacists now or in the future. The model's supply projections do not presently differentiate patient care and non-patient care components of supply though we plan to add this feature to the model. Finally, the BLS 1988 separation rates, although the best predictor among the rate sets studied, shower higher than expected diminution of the workforce after age 40. For example, at age 40, the total separation rate for both male and female is .0164 for the BLS rates vs 0.0016 for physician separation rates. Since the largest segment of the pharmacy workforce is greater than 40 years, the model may underestimate the pharmacist workforce size.
CONCLUSION
The Bureau of Health Professions Pharmacist Supply Model provides three series of estimates of the total number of active pharmacists to the year 2020 by age and gender. It also estimates graduates by gender and degree. It includes annual estimates of international pharmacy graduates and counts of pharmacists leaving the work force by reason of death or retirement. The totals generated by the model compared well with counts from other sources increasing confidence in the model as a predictive tool. The model describes a workforce that is increasingly female and increasingly dominated by holders of the Doctor of Pharmacy degree.
The perspective offered by the model gives health policy makers and health workforce researchers an important tool for estimating numbers of pharmacists and their demographic makeup in the future. While limitations exist, they merely suggest where efforts are needed in research and data collection to improve its predictive capabilities. Amid multiple speculations about the future of pharmacy in the new millennium, this model will serve as a useful adjunct for providing accurate information on the supply of active pharmacists. It should be recognized as an important step in expanding knowledge about the pharmacy workforce through modeling. It also supports pharmacy's recent commitment to collectively look at issues that affect supply and demand. The utility of the model lies in its ability to move forward through time using known available data elements. Supplying the model with more accurate data, such as separation rates that are specific to pharmacists, or better estimates of numbers of U.S. graduates will improve its predictive capabilities. But even in the absence of such data, the model unquestionably serves a purposeful role.
References
1. Beavers N. Feeling the weight: RPh shortages reported across nation as prescription load gets ready to reach four billion units. Drug Topics. 2000;144(1):38-41,47-8.
2. Federal Register, March 16, 2000
3. Knapp KK, Koch MJ, Norton L, Mergener MA. Work patterns of male and female pharmacists: a longitudinal analysis 1960-1989. Eval and Health Prof. 1992;15(2):231-49.
4. Schondelmeyer SW, Mason HL, Miller CS, Kibbe AH. Final report of the national pharmacists' compensation survey: 1990-91. Washington,DC: American Pharmaceutical Association; 1992.
5. Mason HL, D'Elia RP. The supply of pharmacist personnel over time. J Res Pharm Econ. 1994;5(4):125-44.
6. Knapp KK. Pharmacy manpower: implications for pharmaceutical care and health care reform. Am J Hosp Pharm. 1994;51:1212-20.
7. Quiñones AC, Mason HL. Characterizing pharmacy part-time practice. J Am Pharm Assoc. 2000;40:17-25.
8. Shih YT. Trends in full-time pharmacists' labor market characteristics. J Am Pharm Assoc. 2000;40:26-35.
9. Mott DA. Pharmacist job turnover, length of service, and reasons for leaving, 1983-1997. Am J Health-Syst Pharm. 2000;57:975-82.
10. Bond CA, Raehl CL. Changes in pharmacy, nursing, and total personnel staffing in U.S. hospitals, 1989-1998. Am J Health-Syst Pharm. 2000;57:970-4.
11. Vector Research, Inc. Pharmacy manpower project: state and national survey reports. Ann Arbor, MI: Vector Research Inc; 1994.
12. Knapp K, Lipson D, Simpson K. California pharmacy manpower: present and future, part I. California Pharmacist.1986;34;37-44,54.
13. Knapp KK, Paavola F, Manasse H Jr. Models for the supply of pharmacists. Evaluation and the Health Professions. 1990;3:343-63.
14. BPedersen CA, Doucette WR, Gaither CA, Mott DA, Schommer JC. National pharmacist workforce survey: 2000. 2000;www.aacp.org/Resources/Profiles_Reports/manpower.html
15. Maddux MS, Dong BJ, Miller WA, Nelson KM, Raebel MA et al. A vision of pharmacy's future roles, responsibilities, and manpower needs in the United States. Pharmacotherapy 2000;20(8):991-1020.
a.Unpublished data, Bureau of Labor Statistics, 2000.
b.Unpublished data, Bureau of Labor Statistics, 2000 corroborated by a report of 185,000 pharmacists in 1998 in BLS Website, http://stats.bls.gov.ocohome.htm
c.Unpublished data, Bureau of Labor Statistics, 2000.