In cases of acute, grave illness or injury, the medical evaluation may stand alone, particularly if medical evidence establishes that continued service would be deleterious to the servicemember’s health or is not in the best interests of the…Service.
However, when a member’s condition is a chronic impairment, evaluation of the member’s performance of duty by supervisors as indicated, for example, by letters, efficiency reports, credential reports, status of physician medical privileges, or personal testimony may provide better evidence than a clinical estimate by a physician of the servicemember’s ability to perform his or her duties. Particularly in cases of chronic illness, these documents may be expected to reflect accurately a member’s capacity to perform.
Adequate job performance may be considered evidence that a servicemember is fit for duty even though medical evidence indicates questionable physical ability. However, inadequate duty performance shall not be considered as evidence of unfitness…unless it is established that there is a cause and effect relationship….