title: Validity of ICD-9-CM codes for breast, lung and colorectal cancers in three Italian administrative healthcare databases: a diagnostic accuracy study protocol.
abstract: BACKGROUND
  Administrative healthcare databases are useful tools to study healthcare outcomes and to monitor the health status of a population. Patients with cancer can be identified through disease-specific codes, prescriptions and physician claims, but prior validation is required to achieve an accurate case definition. The objective of this protocol is to assess the accuracy of International Classification of Diseases Ninth Revision-Clinical Modification (ICD-9-CM) codes for breast, lung and colorectal cancers in identifying patients diagnosed with the relative disease in three Italian administrative databases.
  
  
  METHODS
  Data from the administrative databases of Umbria Region (910,000 residents), Local Health Unit 3 of Napoli (1,170,000 residents) and Friuli--Venezia Giulia Region (1,227,000 residents) will be considered. In each administrative database, patients with the first occurrence of diagnosis of breast, lung or colorectal cancer between 2012 and 2014 will be identified using the following groups of ICD-9-CM codes in primary position: (1) 233.0 and (2) 174.x for breast cancer; (3) 162.x for lung cancer; (4) 153.x for colon cancer and (5) 154.0-154.1 and 154.8 for rectal cancer. Only incident cases will be considered, that is, excluding cases that have the same diagnosis in the 5 years (2007-2011) before the period of interest. A random sample of cases and non-cases will be selected from each administrative database and the corresponding medical charts will be assessed for validation by pairs of trained, independent reviewers. Case ascertainment within the medical charts will be based on (1) the presence of a primary nodular lesion in the breast, lung or colon-rectum, documented with imaging or endoscopy and (2) a cytological or histological documentation of cancer from a primary or metastatic site. Sensitivity and specificity with 95% CIs will be calculated.
  
  
  RESULTS
  Study results will be disseminated widely through peer-reviewed publications and presentations at national and international conferences.
authors.affiliation: Health Planning Service, Regional Health Authority of Umbria, Perugia, Italy.
authors.forename: Iosief
authors.initials: I
authors.lastname: Abraha
authors.affiliation: Epidemiology and Biostatistic Unit, Centro di Riferimento Oncologico Aviano, Aviano, Italy.
authors.forename: Diego
authors.initials: D
authors.lastname: Serraino
authors.affiliation: Health Planning Service, Regional Health Authority of Umbria, Perugia, Italy.
authors.forename: Gianni
authors.initials: G
authors.lastname: Giovannini
authors.affiliation: Public Health Department, University of Perugia, Perugia, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Stracci
authors.affiliation: Health ICT Service, Regional Health Authority of Umbria, Perugia, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Casucci
authors.affiliation: Health ICT Service, Regional Health Authority of Umbria, Perugia, Italy.
authors.forename: Giuliana
authors.initials: G
authors.lastname: Alessandrini
authors.affiliation: Epidemiology and Biostatistic Unit, Centro di Riferimento Oncologico Aviano, Aviano, Italy.
authors.forename: Ettore
authors.initials: E
authors.lastname: Bidoli
authors.affiliation: Dipartimento di Oncologia, Azienda Ospedaliera Perugia, Perugia, Italy.
authors.forename: Rita
authors.initials: R
authors.lastname: Chiari
authors.affiliation: Department of Digestive Surgery and Liver Unit, University of Perugia, Perugia, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Cirocchi
authors.affiliation: Health ICT Service, Regional Health Authority of Umbria, Perugia, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: De Giorgi
authors.affiliation: Health ICT Service, Regional Health Authority of Umbria, Perugia, Italy.
authors.forename: David
authors.initials: D
authors.lastname: Franchini
authors.affiliation: Registro Tumori Regione Campania, ASL NA3 Sud, Brusciano, Italy.
authors.forename: Maria Francesca
authors.initials: MF
authors.lastname: Vitale
authors.affiliation: Registro Tumori Regione Campania, ASL NA3 Sud, Brusciano, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Fusco
authors.affiliation: Health Planning Service, Regional Health Authority of Umbria, Perugia, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Montedori
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000175:diagnosis*; D059019:Clinical Coding / Q000592:standards*; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D016208:Databases, Factual; D005260:Female; D006801:Humans; D038801:International Classification of Diseases / Q000592:standards*; D007558:Italy; D008175:Lung Neoplasms / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: administrative database; breast, lung and colorectal cancers; validating ICD-9 codes