Premature discharge from military service : risk factors and preventive interventions

The tasks and capabilities of the Swedish Armed Forces are changing to meet new threats all around the world. With the sharp decrease in number of enlisted soldiers, selection is more important than ever. It is also important to prevent soldiers from leaving military service prematurely i.e. from being discharged. The present work has sought to deepen our knowledge in this important field.

The overall aim of the work presented in this thesis was to identify risk factors and to describe and analyze the influence of preventive interventions on premature discharge from military service. This was to be achieved by evaluating both a test for selection to physically demanding service and screening tests for identifying risk factors for discharge present at the start of army conscript service. Finally, a specially-tailored comprehensive intervention programme was implemented.

Male conscripts (n=1807) from different army units participated in the four studies during their military service. The investigations were applied within the first week of the conscripts service. Cases for premature discharge were recorded during service. The lower-limb functional capacity test, the ranger test, was evaluated in a ranger unit. A musculoskeletal screening protocol (MSP) with the main purpose of identifying personnel at risk of premature discharge was developed. The MSP comprised a questionnaire, a lower-limb-loading test with pain-intensity ratings, assessment of passive range of motion, and muscular endurance tests. The comprehensive intervention was implemented in an artillery unit, a ranger unit and an engineer unit. The intervention comprised a course for officers, the MSP followed by early rehabilitation, organised, systematic co-operation between officers and physiotherapist, and physical training programmes.

The ranger test had high discriminating ability and predictive value for premature discharge caused by knee or back problems during strenuous military ranger training. The set of four lower-limb-loading tests was reliable and valid in detecting knee pain. Musculoskeletal complaints or injuries current at the start of the training were common (33-41 %) and independently and significantly associated with premature discharge. Being physically inactive, exposed to high physical load during the first three months of service, perceiving poor mental health, being mentally unprepared or smoking were also predictors of premature discharge. The discharge rate was lower in all three units after the intervention programme had been implemented compared to the previous year.

In conclusion, different risk factors for premature discharge can be identified at the time conscript service begins. A supplemented selection procedure during enrolment for ranger conscripts was important for conscripts who would be highly loaded. The ranger test could be a supplement in the selection of applicants for ranger service, where a minimally acceptable performance standard is suggested. Fewer prematurely discharged conscripts, in comparison with historical data, indicates that the present intervention programme implemented in three army units was effective. The findings provide useful information on potential risk factors, and this highlights the need for improved pre-enlistment examination and early preventive strategies.

List of scientific papers

I. Larsson H, Harms-Ringdahl K (2006). "A lower-limb functional capacity test for enlistment into Swedish Armed Forces ranger units." Mil Med 171(11): 1065-70
https://pubmed.ncbi.nlm.nih.gov/17153543

II. Larsson H, Larsson M, Osterberg H, Harms-Ringdahl K (2008). "Screening tests detect knee pain and predict discharge from military service." Mil Med 173(3): 259-65
https://pubmed.ncbi.nlm.nih.gov/18419028

III. Larsson H, Broman L, Harms-Ringdahl K (2009). "Individual risk factors associated with premature discharge from military service." Mil Med 174(1): 9-20
https://pubmed.ncbi.nlm.nih.gov/19216293

IV. Larsson H, Tegern M, Harms-Ringdahl K (2009). "Influence of a comprehensive intervention programme on premature discharge outcomes from military service - a longitudinal study." (Manuscript)