title: Comparability, diagnostic validity and completeness of Nigerian cancer registries.
abstract: BACKGROUND
  Like many countries in Africa, Nigeria is improving the quality and coverage of its cancer surveillance. This work is essential to address this growing category of chronic diseases, but is made difficult by economic, geographic and other challenges.
  
  
  OBJECTIVE
  To evaluate the completeness, comparability and diagnostic validity of Nigeria's cancer registries.
  
  
  METHODS
  Completeness was measured using children's age-specific incidence (ASI) and an established metric based on a modified Poisson distribution with regional comparisons. We used a registry questionnaire as well as percentages of death-certificate-only cases, morphologically verified cases, and case registration errors to examine comparability and diagnostic validity.
  
  
  RESULTS
  Among the children's results, we found that over half of all cancers were non-Hodgkin lymphoma. There was also evidence of incompleteness. Considering the regional completeness comparisons, we found potential evidence of cancer-specific general incompleteness as well as what appears to be incompleteness due to inability to diagnose specific cancers. We found that registration was generally comparable, with some exceptions. Since autopsies are not common across Nigeria, coding for both them and death-certificate-only cases was also rare. With one exception, registries in our study had high rates of morphological verification of female breast, cervical and prostate cancers.
  
  
  CONCLUSIONS
  Nigeria's registration procedures were generally comparable to each other and to international standards, and we found high rates of morphological verification, suggesting high diagnostic validity. There was, however, evidence of incompleteness.
authors: Medical Scientist Training Program, University of Minnesota, 420 Delaware Street SE, B681 Mayo Building, MMC 293, Minneapolis, MN 55414, USA. Electronic address: haddad@umn.edu.
authors: B J S
authors: BJ
authors: al-Haddad
authors: Institute of Human Virology, Nigeria, Pent House, Maina Court, Plot 252, Herbert Macaulay Way, Central Business District, P.O. Box 9396, Garki, Abuja, Nigeria. Electronic address: elima.jedyagba@gmail.com.
authors: Elima
authors: E
authors: Jedy-Agba
authors: Institute of Human Virology, Nigeria, Pent House, Maina Court, Plot 252, Herbert Macaulay Way, Central Business District, P.O. Box 9396, Garki, Abuja, Nigeria. Electronic address: imanueloga@gmail.com.
authors: Emmanuel
authors: E
authors: Oga
authors: University of Nigeria Teaching Hospital, Ituku-Ozalla, Enugu, Enugu State, Nigeria. Electronic address: ezeome95@gmail.com.
authors: E R
authors: ER
authors: Ezeome
authors: University of Port Harcourt Teaching Hospital, East-West Road, Port Harcourt, Rivers State, Nigeria. Electronic address: christopherobiorah@yahoo.com.
authors: Christopher C
authors: CC
authors: Obiorah
authors: Professor Olikoye Ransome-Kuti (Midwestern Nigeria) Cancer Registry, Department of Surgery, University of Benin Teaching Hospital, P.M.B. 1111, Benin City, Edo State, Nigeria. Electronic address: michaelokobia@yahoo.com.
authors: Michael
authors: M
authors: Okobia
authors: Ibadan Cancer Registry, Department of Pathology, University College Hospital, P.M.B. 5116, Ibadan, Nigeria. Electronic address: f_ogunbiyi@yahoo.com.
authors: J Olufemi
authors: JO
authors: Ogunbiyi
authors: Nnewi Cancer Registry, Nnamdi Azikiwe University Teaching Hospital, P.M.B. 5025, Nnewi, Anambra State, Nigeria. Electronic address: ukahcornelius@yahoo.com.
authors: Cornelius Ozobia
authors: CO
authors: Ukah
authors: Ife Ijesha Cancer Registry, Obafemi Awolowo University Teaching Hospitals, PO Box 1923, Ile Ife, Osun State, Nigeria. Electronic address: abidemi.omonisi@gmail.com.
authors: Abidemi
authors: A
authors: Omonisi
authors: Nnewi Cancer Registry, Nnamdi Azikiwe University Teaching Hospital, P.M.B. 5025, Nnewi, Anambra State, Nigeria. Electronic address: xnwofor@yahoo.com.
authors: A M E
authors: AM
authors: Nwofor
authors: Abuja Cancer Registry, National Hospital, Abuja, Plot 132, Central District (Phase 11), P.M.B. 425, Garki-Abuja, Federal Capital Territory, Nigeria. Electronic address: figbinoba@gmail.com.
authors: Festus
authors: F
authors: Igbinoba
authors: Institute of Human Virology, Nigeria, Pent House, Maina Court, Plot 252, Herbert Macaulay Way, Central Business District, P.O. Box 9396, Garki, Abuja, Nigeria. Electronic address: cadebamowo@yahoo.com.
authors: Clement
authors: C
authors: Adebamowo
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009369:Neoplasms / Q000175:diagnosis* / Q000453:epidemiology*; D009549:Nigeria / Q000453:epidemiology; D012042:Registries / Q000592:standards* / Q000706:statistics & numerical data; D011795:Surveys and Questionnaires; D054928:Validation Studies as Topic
keywords: Africa; Cancer; Cancer registration; Comparability; Morphological verification; Nigeria; Surveillance; Validity