Table 1

 Case and control ICD-9 diagnostic codes

Diagnostic set, specific diagnosisICD-9 codes
*Also treated as independent control diagnoses.
Respiratory grouping460–519
Diagnoses other than respiratory
    Infectious (other than tuberculosis)001–009, 020–139
    Endocrine, immune, and metabolic240–279
    Blood and haematopoietic280–289
    Mental disorders290–319
    Nervous system320–389
    Gastrointestinal*520–579
    Genitourinary*580–629
    Skin and subcutaneous680–709
    Musculoskeletal and connective tissues710–739