Number of antibiotics prescribed per disease class (percentages in parenthesis). ‘Unknown’ diagnosis class represents encounters for which multiple diagnoses (from different classes) were recorded per appropriateness tier and, therefore, diagnoses could not be categorized into any specific class. (A–B) Certain infectious and parasitic diseases; (C) Malignant neoplasms; (D) In Situ neoplasms/Benign neoplasms/Neoplasms of uncertain or unknown behaviour/Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism; (E) Endocrine, nutritional, and metabolic diseases; (F) Mental and Behavioural disorders; (G) Diseases of the nervous system; (H) Diseases of the eye and adnexa/Diseases of the ear and mastoid process; (I) Diseases of the circulatory system; (J) Diseases of the respiratory system; (K) Diseases of the digestive system; (L) Diseases of the skin and subcutaneous tissue; (M) Diseases of the musculoskeletal system and connective tissue; (N) Diseases of the genitourinary system; (O) Pregnancy, childbirth, and the puerperium; (P) Certain conditions originating in the perinatal period; (Q) Congenital malformations, deformations and chromosomal abnormalities; (R) Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified; (S) Injury, poisoning and certain other consequences of external causes (Injuries); (T) Injury, poisoning and certain other consequences of external causes (Injuries/Effects of foreign body entering through natural orifice/Burns and corrosions/Frostbite, et cetera); (U) Codes for special purposes; (V) External causes of morbidity and mortality (Transport accidents); (W) External causes of morbidity and mortality (Other external causes of accidental injury); (X) External causes of morbidity and mortality (Other external causes of accidental injury/Intentional self-harm/Assault); (Y) External causes of morbidity and mortality (Assault/Event of undetermined intent/Legal intervention and operations of war/Complications of medical and surgical care, et cetera); (Z) Factors influencing health status and contact with health services.