Appendix Table 1.

Study classification of the primary cause for admission.

ICD-10	ICD-9	Classification of Disease
A00-B99	001–009	Infectious and parasitic diseases
C00-D48	140–239	Neoplasms
D50-D89	280–289	Diseases of the blood and blood-forming organs
E00-E90	240–279	Endocrine, nutritional and metabolic diseases
F00–F99	290–319	Mental and behavioral disorders
G00-G99	320–359	Diseases of the nervous system
H00–H59	360–379	Diseases of the eye and adnexa
H60–H95	380–389	Diseases of the ear and mastoid process
I00–I99	390–459	Diseases of the circulatory system
J00-J99	460–519	Diseases of the respiratory system
K00–K93	520–579	Diseases of the digestive system
L00-L99	680–709	Diseases of the skin and subcutaneous tissue
M00-M99	710–739	Diseases of the musculoskeletal system and connective tissue
N00–N99	580–629	Diseases of the genitourinary system
O00–O99	630–676	Pregnancy, childbirth and the puerperium
P00–P96	760–779	Conditions originating in the perinatal period
Q00-Q99	740–759	Congenital abnormalities
R00-R99	780–799	Symptoms, signs and abnormal clinical and laboratory findings
S00-T98	800–999	Injury, poisoning and other consequences of external causes
V01–Y98	E800-E999	External causes of morbidity and mortality
Z00-Z99	V01–V82	Factors influencing health status and contact with health services