Forecasting the global shortage of physicians: an economic- and needs-based approach Richard M Scheffler,a Jenny X Liu,b Yohannes Kinfu c & Mario R Dal Poz d Objective Global achievements in health may be limited by critical shortages of health-care workers. To help guide workforce policy, we estimate the future demand for, need for and supply of physicians, by WHO region, to determine where likely shortages will occur by 2015, the target date of the Millennium Development Goals. Methods Using World Bank and WHO data on physicians per capita from 1980 to 2001 for 158 countries, we employ two modelling approaches for estimating the future global requirement for physicians. A needs-based model determines the number of physicians per capita required to achieve 80% coverage of live births by a skilled health-care attendant. In contrast, our economic model identifies the number of physicians per capita that are likely to be demanded, given each country’s economic growth. These estimates are compared to the future supply of physicians projected by extrapolating the historical rate of increase in physicians per capita for each country. Findings By 2015, the global supply of physicians appears to be in balance with projected economic demand. Because our measure of need reflects the minimum level of workforce density required to provide a basic health service that is met in all but the least developed countries, the needs-based estimates predict a global surplus of physicians. However, on a regional basis, both models predict shortages for many countries in the WHO African Region in 2015, with some countries experiencing a needs-based shortage, a demand-based shortage, or both. Conclusion The type of policy intervention needed to alleviate projected shortages, such as increasing health-care training or adopting measures to discourage migration, depends on the type of shortage projected. Bulletin of the World Health Organization 2008;86:516–523. الرتجمة العربية لهذه الخالصة يف نهاية النص الكامل لهذه املقالة. .Une traduction en français de ce résumé figure à la fin de l’article. Al final del artículo se facilita una traducción al español Introduction vision. Using the most updated infor- estimates of shortages by country in mation on the supply of physicians over Africa and discuss their implications The world health report 2006: working a 20-year period, we project the size for different workforce policy choices. together for health has brought renewed of the future global need for, demand attention to the global human resources for and supply of physicians to year required to produce health.1 It esti- Methods 2015, the target date for the Millen- mated that 57 countries have an abso- nium Development Goals (MDGs).2 For illustrative purposes, we provide lute shortage of 2.3 million physicians, a stylized version of the conceptual Needs-based estimates use an exog- nurses and midwives. These shortages framework we employed for forecast- enous health benchmark to judge the suggest that many countries have insuf- ing physician numbers in Fig. 1. First, adequacy of the number of physi- ficient numbers of health professionals we project the supply in the per capita to deliver essential health interventions, cians required to meet MDG targets. number of physicians (S) based on his- such as skilled attendance at birth and Demand estimates are based on a coun- torical data on physician numbers for immunization programmes. However, try’s economic growth and the increase each country; this serves as a baseline these estimates do not take into account in health-care spending that results against which different forecasts can be the ability of countries to recruit and re- from it, which primarily goes towards evaluated. We employ two forecasting tain these workers, nor are they specific worker salaries. We then compare the methods. The forecast for the needs- enough to inform policy-makers about needs-based and demand-based esti- based estimate (N) is determined by how, and to what extent, health work- mates to the projected supply of physi- calculating the number of physicians force investment should be channelled cians, extrapolated based on historical that would be required to reach The into training of different professions. trends. Our results point to dramatic world health report 2006 goal of having This paper focuses on physicians, shortages of physicians in the WHO 80% of live births attended by a skilled who serve a key role in health-care pro- African Region by 2015. We provide health worker.3 The second forecasting a School of Public Health and the Goldman School of Public Policy, University of California, Berkeley, CA, United States of America. b Global Center for Health Economics and Public Policy, School of Public Health, University of California, Berkeley, CA, USA. c Department of Health Statistics and Informatics, World Health Organization, Geneva, Switzerland. d Department of Human Resources for Health, World Health Organization, Geneva, Switzerland. Correspondence to Richard Scheffler (e-mail: [email protected]). doi:10.2471/BLT.07.046474 (Submitted: 2 August 2007 – Revised version received: 12 November 2007 – Accepted: 22 November 2007 – Published online: 3 April 2008 ) 516 Bulletin of the World Health Organization | July 2008, 86 (7) Research Richard Scheffler et al. Forecasting the global shortage of physicians method reflects the demand for physi- Fig. 1. Conceptual forecasting framework cians in each country as determined by economic growth (D1 and D2). With 4.50 these different estimates, shortages or 4.00 surpluses can be calculated. For exam- 3.50 ple, by year 8, about 3.5 physicians per 3.00 1000 population will be needed com- 2.50 pared to the projected supply of 3.0 per 1000, producing a 0.5 per 1000 short- 2.00 age. In comparison, 4.0 per 1000 1.50 will be demanded according to the 1.00 0.50 scenario represented by D1, resulting in a demand-based shortage of about Physicians (per 1000 population) 0.00 1.0 physicians per 1000. A different 1 2 3 4 5 6 7 8 scenario can arise if supply exceeds Year demand, as represented by D2, result- S: Projected supply extrapolated based on the historical growth in physicians per 1000 population ing in a surplus. We can then multiply D1: Forecasted demand based on economic growth (scenario with a projected shortage) this estimated shortage by projected D2: Forecasted demand based on economic growth (scenario with a projected surplus) population numbers to calculate the N: Forecasted need based on reaching benchmark level of service provision absolute deficit of the numbers of physicians. In this illustrative case, sumes that skills mix in health service labour is the principle component.5–9 the needs-based shortage exceeds the delivery remains constant. The needs- This method has also been employed in demand-based shortage. This frame- based model estimates the following other forecasts of physician demand.10 work can be applied at the country, equation for all countries i at time t: This approach estimates the following regional and global levels of analyses, relationship for country i at time t: depending on the level of aggregation of –1 sin (% coverageit) = β0 + β1 × physician numbers. ln(physicians per 1000 populationit) + ln(physicians per 1000 populationit) = We now describe our estimation μi + ηt + δit γ0 + γ1 × ln(GNI per capitait–5) + γ2 × procedures more formally. First, base- income leveli + μi + ζit line supply projections to the year where μi and ηt reflect country and 2015 were estimated using the histori- time fixed effects, respectively, δit where μi reflects a vector of country fixed cal growth rate of physician densities in is a random error term, and β and β effects,ζ it is the disturbance term, and γ each country. The following regression 0 1 0 are unknown parameters to be estimated and γ1 are unknown parameters to be esti- equation was run for each country for from the model. This threshold density mated from the model. GNI per capita is time t = {1980, … , 2001}: figure, along with population estimates lagged 5 years to account for time required for future years, was subsequently used for economic growth to affect health- ln(physicians per 1000 populationt ) = to calculate the number of physicians care spending and, in turn, influence α0 + α1 × yeart + εt that would be needed in each country to changes in the health-care system and the attain the MDG of 80% coverage of live workforce. Because GNI data were only where εt is the random disturbance births. We opted for the sin–1 transforma- available until 2002 at the time of data α α term, and 0 and 1 are unknown tion because it is more consistent with assembly, values for 2003–2010 were parameters to be estimated from the statistical theory; the transformation of predicted using the historical growth rate. model. This exponential growth model the dependent variable, which is a pro- For each country at time t, the growth rate assumes that current trends in the growth portion, results in normally distributed in GNI per capita was calculated as: of physician numbers will continue as responses (asymptotically). The sin–1-log they have historically for each country. model also achieved the highest R² and exp(λ1) – 1 The needs-based approach is based best goodness-of-fit to the data as mea- on an sin–1-log model that relates phy- sured by the deviance.4 This approach from the equation: sician density with coverage of skilled is similar to that followed in The world birth attendants, weighted by popula- health report 2006. ln(GNI per capitat ) = λ0 + λ1 × tion size. This model is used to identify The demand-based approach uti- yeart + νt a level of physician density below which lizes gross national income (GNI) per virtually no country has achieved 80% capita as the predictor of demand for where νt is the disturbance term, and coverage.