Analysis of Health Factors as Predictors for the Functioning of Military Personnel: Study of the Factors That Predict Fitness for Duty and Medical Costs of Soldiers of the Royal Netherlands Army

In 1998, the Royal Netherlands Army introduced a new examination system, which is based on the "workload-capability" model, to replace the old system, which focused on diagnosis and was solely based on the detection of diseases and infirmities. In a randomized controlled study, we found that soldiers recruited under the new system displayed a statistically significant higher number of days fit-for-duty and incurred lower medical costs than solders recruited under the old system. To gain a better understanding of the reasons for these differences, we studied the association between these results and information collected about the soldiers. In the course of the study, we collected various types of information about the study participants (e.g., education, deployment). During the study, soldiers were asked to complete a questionnaire twice a year, its content based in part on a periodic occupational health examination questionnaire commonly used in The Netherlands. We found that the following factors influenced fitness for duty and medical consumption: education, injuries, actual operational deployment, and the examination system itself. The superior performance of the new RNLA Basic Medical Requirements (BMEKL) system seems partly attributable to the assessment of the ability to meet the task-specific requirements. The primary mechanism is as yet undiscovered.