title: Nursing productivity: evolution of a systems model.
mesh_terms: D003953:Diagnosis-Related Groups; D004526:Efficiency; D006801:Humans; D008888:Military Nursing; D008962:Models, Theoretical; D009326:Naval Medicine; D009741:Nursing Staff, Hospital / Q000458:organization & administration*; D010361:Patients / Q000145:classification; D013598:Systems Theory; D014481:United States