NIVEL, Netherlands Institute for Health Services Research, Otterstraat 118-124, 3513 CR Utrecht, The Netherlands.
Hum Resour Health. 2013 Jul 16;11:31. doi: 10.1186/1478-4491-11-31.
Health workforce projections are important instruments to prevent imbalances in the health workforce. For both the tenability and further development of these projections, it is important to evaluate the accuracy of workforce projections. In The Netherlands, health workforce projections have been done since 2000 to support health workforce planning. What is the accuracy of the techniques of these Dutch general practitioner workforce projections?
We backtested the workforce projection model by comparing the ex-post projected number of general practitioners with the observed number of general practitioners between 1998 and 2011. Averages of historical data were used for all elements except for inflow in training. As the required training inflow is the key result of the workforce planning model, and has actually determined past adjustments of training inflow, the accuracy of the model was backtested using the observed training inflow and not an average of historical data to avoid the interference of past policy decisions. The accuracy of projections with different lengths of projection horizon and base period (on which the projections are based) was tested.
The workforce projection model underestimated the number of active Dutch general practitioners in most years. The mean absolute percentage errors range from 1.9% to 14.9%, with the projections being more accurate in more recent years. Furthermore, projections with a shorter projection horizon have a higher accuracy than those with a longer horizon. Unexpectedly, projections with a shorter base period have a higher accuracy than those with a longer base period.
According to the results of the present study, forecasting the size of the future workforce did not become more difficult between 1998 and 2011, as we originally expected. Furthermore, the projections with a short projection horizon and a short base period are more accurate than projections with a longer projection horizon and base period. We can carefully conclude that health workforce projections can be made with data based on relatively short base periods, although detailed data are still required to monitor and evaluate the health workforce.
卫生人力预测是预防卫生人力失衡的重要工具。为了使这些预测具有可持续性并得到进一步发展，评估劳动力预测的准确性非常重要。在荷兰，自 2000 年以来，一直进行卫生人力预测，以支持卫生人力规划。这些荷兰普通科医生劳动力预测技术的准确性如何？
我们通过将 1998 年至 2011 年期间实际的普通科医生数量与预测的普通科医生数量进行比较，对劳动力预测模型进行了回溯测试。除培训流入量外，所有要素均使用历史数据平均值。由于所需的培训流入量是劳动力规划模型的关键结果，并且实际上决定了过去培训流入量的调整，因此使用实际的培训流入量而不是历史数据平均值来测试模型的准确性，以避免过去政策决策的干扰。测试了具有不同预测期限和基期（预测所依据的期限）的预测的准确性。
劳动力预测模型在大多数年份都低估了荷兰活跃普通科医生的数量。平均绝对百分比误差范围为 1.9%至 14.9%，最近几年的预测准确性更高。此外，预测期限较短的预测比预测期限较长的预测更准确。出乎意料的是，预测基期较短的预测比预测基期较长的预测更准确。
根据本研究的结果，我们最初预计，1998 年至 2011 年间，预测未来劳动力规模不会变得更加困难。此外，预测期限较短且基期较短的预测比预测期限较长和基期较长的预测更准确。我们可以谨慎地得出结论，尽管详细数据仍然是监测和评估卫生劳动力所必需的，但可以使用基于相对较短基期的数据来进行卫生劳动力预测。
