Box 1. Inclusion criteria and search strategy
CriteriaDescription
Inclusion criteria
PopulationAdults (age ≥16 years)
Intellectual disabilities
TopicLong-term health conditions
Preventative health services, health checks, and screening
Accessibility of primary healthcare services
SettingPrimary care
Study typeQuantitative studies

  • Controlled trials of interventions (randomised or non-randomised)

  • Observational studies (cohort, case control) of primary health care

  • Analyses of routine primary care data

 Qualitative studies

  • Qualitative interview or focus group studies

  • Questionnaire studies

Exclusion criteria
PopulationAge <16 years old
Without intellectual disabilities
TopicMental health conditions
SettingMental health services
Secondary care or hospital setting
Residential
Study typeEpidemiological studies
Economic evaluations
Systematic reviews
Case studies or case reports
Search strategy
DatabasesCINAHL, Cochrane, IBSS, PsycINFO, PubMed, ScienceDirect, Web of Knowledge
Manual searchingReference lists of all eligible studies and identified systematic reviews
Hand-searching a sample of selected relevant journals
(Relevant journals searched include: Advances in Mental Health and Learning Disabilities; American Journal on Intellectual and Developmental Disabilities (American Journal on Mental Retardation); Journal of Applied Research in Intellectual Disabilities; Journal of Intellectual Disability Research; Journal of Learning Disabilities; Journal of Policy and Practice in Intellectual Disabilities; Developmental Disabilities Research Reviews)
Forward citationsPerformed for all included studies (using Web of Science)
RestrictionsEnglish language only
DatesDatabase: January 1966 (or inception) to June 2016. Manual and forward citation search completed January 2017