title: Increased consultation frequency in primary care, a risk marker for cancer: a case-control study.
abstract: OBJECTIVE
  To identify early diagnostic profiles such as diagnostic codes and consultation patterns of cancer patients in primary care one year prior to cancer diagnosis.
  
  
  METHODS
  Total population-based case-control study.
  
  
  METHODS
  4562 cancer patients and 17,979 controls matched by age, sex, and primary care unit. Data were collected from the Swedish Cancer Register and the Regional Healthcare Database.
  
  
  METHODS
  We identified cancer patients in the Västra Götaland Region of Sweden diagnosed in 2011 with prostate, breast, colorectal, lung, gynaecological, and skin cancers including malignant melanoma. We studied the symptoms and diagnoses identified by diagnostic codes during a diagnostic interval of 12 months before the cancer diagnosis.
  
  
  METHODS
  Consultation frequency, symptom density by cancer type, prevalence and odds ratios (OR) for the diagnostic codes in the cancer population as a whole.
  
  
  RESULTS
  The diagnostic codes with the highest OR were unspecified lump in breast, neoplasm of uncertain behaviour, and abnormal serum enzyme levels. The codes with the highest prevalence were hyperplasia of prostate, other skin changes and abdominal and pelvic pain. The frequency of diagnostic codes and consultations in primary care rose in tandem 50 days before diagnosis for breast and gynaecological cancer, 60 days for malignant melanoma and skin cancer, 80 days for prostate cancer and 100 days for colorectal and lung cancer.
  
  
  CONCLUSIONS
  Eighty-seven percent of patients with the most common cancers consulted a general practitioner (GP) a year before their diagnosis. An increase in consultation frequency and presentation of any symptom should raise the GP's suspicion of cancer. Key points Knowledge about the prevalence of early symptoms and other clinical signs in cancer patients in primary care remains insufficient. • Eighty-seven percent of the patients with the seven most common cancers consulted a general practitioner 12 months prior to cancer diagnosis. • Both the frequency of consultation and the number of symptoms and diseases expressed in diagnostic codes rose in tandem 50-100 days before the cancer diagnosis. • Unless it is caused by a previously known disease, an increased consultation rate for any symptom should result in a swift investigation or referral from primary care to confirm or exclude cancer.
authors.affiliation: a Department of Public Health and Community Medicine/Primary Health Care , Institute of Medicine at Sahlgrenska Academy, University of Gothenburg , Gothenburg , Sweden ;
authors.forename: Marcela
authors.initials: M
authors.lastname: Ewing
authors.affiliation: b Department of Surgery , Institute of Clinical Sciences at Sahlgrenska Academy, University of Gothenburg , Gothenburg , Sweden ;
authors.forename: Peter
authors.initials: P
authors.lastname: Naredi
authors.affiliation: c Centre of Registers , Gothenburg , Sweden ;
authors.forename: Szilard
authors.initials: S
authors.lastname: Nemes
authors.affiliation: d Regional Cancer Center West, Sahlgrenska University Hospital , Gothenburg , Sweden.
authors.forename: Chenyang
authors.initials: C
authors.lastname: Zhang
authors.affiliation: a Department of Public Health and Community Medicine/Primary Health Care , Institute of Medicine at Sahlgrenska Academy, University of Gothenburg , Gothenburg , Sweden ;
authors.forename: Jörgen
authors.initials: J
authors.lastname: Månsson
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D016208:Databases, Factual; D005260:Female; D058005:General Practitioners; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000175:diagnosis / Q000453:epidemiology; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data*; D011320:Primary Health Care / Q000706:statistics & numerical data*; D012042:Registries; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology
keywords: Cancer; ICD codes; Sweden; consultation; diagnosis; general practice; primary healthcare