Table 2. Set of ICD-10 codes used in the selection of patients.

As main diagnosis
All I codes	Diseases of the circulatory system
J819	Pulmonary oedema
J13	Pneumonia due to Streptococcus pneumoniae
J15	Bacterial pneumonia, not elsewhere classified
J18	Pneumonia, organism unspecified
R33	Retention of urine
As main or secondary diagnosis
I803	Phlebitis and thrombophlebitis of lower extremities, unspecified
I269	Pulmonary embolism without mention of acute cor pulmonale
L899	Decubitus ulcer and pressure area, unspecified
M243	Pathological dislocation and subluxation of joint, not elsewhere classified
M244	Recurrent dislocation and subluxation of joint
S730	Dislocation, sprain and strain of joint and ligaments of hip
T810	Haemorrhage and haematoma complicating a procedure, not elsewhere classified
T813	Disruption of operation wound, not elsewhere classified
T814	Infection following a procedure, not elsewhere classified
T840	Mechanical complication of internal joint prosthesis
T845	Infection and inflammatory reaction due to internal joint prosthesis
T933	Sequelae of dislocation, sprain and strain of lower limb

ICD-10, the 10th revision of the International Classification of Diseases.