title: Application and applicability of non-invasive risk models for predicting undiagnosed prevalent diabetes in Africa: A systematic literature search.
abstract: OBJECTIVE
  Prediction algorithms are increasingly advocated in diabetes screening strategies, particularly in developing countries. We conducted a systematic review to assess the application and applicability of existing non-invasive prevalent diabetes risk models to populations within Africa.
  
  
  METHODS
  systematic review data sources A systematic search of English literatures in Medline via PubMed from 1999 until June, 2014. Study selection Included studies had to report on the development, validation or implementation of a model that was primarily constructed to predict prevalent undiagnosed diabetes using non-laboratory based predictors.
  
  
  METHODS
  Data were extracted on the type of statistical model, type and range of predictors in the model, performance measures in both internal and external validation, and whether the model was developed from, validated or implemented in an African population.
  
  
  RESULTS
  Twenty-three studies reporting on non-invasive prevalent diabetes models were identified. Ten from Europe (some with multiethnic populations), nine models were developed among Asian population, two from the USA and two from the Middle-East. The c-statistics for these models ranged from 0.65 to 0.88 in the development studies, and from 0.63 to 0.80 in the validation studies. Twenty models were validated, and none in Africa. Among predictors commonly included in models, parental/family history of diabetes and personal history of hypertension appear to be more prone to measurement errors in the African context.
  
  
  CONCLUSIONS
  Existing prevalent diabetes prediction models have not been applied to African populations, and issues with the measurement of key predictors make their applicability likely inaccurate.
authors.affiliation: Department of Community Medicine, University of Oslo, Oslo, Norway; Health of Populations in Transition (HoPiT) Research Group, Faculty of Medicine and Biomedical Sciences, The University of Yaoundé 1, Yaoundé, Cameroon. Electronic address: vivimbanya@yahoo.com.
authors.forename: Vivian
authors.initials: V
authors.lastname: Mbanya
authors.affiliation: Department of Community Medicine, University of Oslo, Oslo, Norway.
authors.forename: Akhtar
authors.initials: A
authors.lastname: Hussain
authors.affiliation: Non-Communicable Diseases Research Unit, South African Medical Research Council & Department of Medicine, University of Cape Town, Cape Town, South Africa.
authors.forename: Andre Pascal
authors.initials: AP
authors.lastname: Kengne
mesh_terms: D000349:Africa / Q000453:epidemiology; D044383:Black People / Q000706:statistics & numerical data*; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis* / Q000208:ethnology*; D006801:Humans; D015233:Models, Statistical; D011237:Predictive Value of Tests; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors
keywords: Africa; Diabetes mellitus; Non-invasive risk scores; Screening