Development of a health assessment instrument for people with intellectual disabilities: a Delphi study.

Background: People with intellectual disabilities (IDs) experience health inequalities. Applying health assessments is one way of diminishing these inequalities. A health assessment instrument can support general practitioners (GPs) in providing better medical care to people with ID.

Objectives: The aim of this study was to determine which items should be part of a health assessment instrument for people with ID to be used in primary care.

Methods: This Delphi consensus study was conducted among 24 GP experts and 21 ID physicians. We performed three anonymous sequential online questionnaire rounds. We started with 82 'general' items and 14 items concerning physical and additional examinations derived from the international literature and a focus group study among Dutch GPs. We definitely included items if more than 75% of the GP experts agreed on their inclusion.

Results: The participation rate in all rounds was above 88%. The expert groups proposed 10 new items. Consensus was reached on 64 'general' items related to highly prevalent diseases, public health and health promotion. Consensus was also reached on 18 physical and additional examination items.

Conclusions: For the first time, experts in a Delphi study were able to arrive at a selection of items for a health assessment instrument for people with ID. The overall agreement among the GPs and ID physicians was good. Because the experts prefer that patients complete the health assessment questionnaire at home, questions that cover these items must be formulated clearly.