Psychometric Properties of Instruments to Assess Movement Disorders in People With Intellectual Disabilities Using Antipsychotics: A Systematic Literature Review.

The review included only 10 studies, and four of them had 2 to 7 participants, so the findings are based on a very small evidence base. The included studies were heterogeneous, so the authors could not combine their results in a meta-analysis. Most studies were published more than two decades ago, and all instruments relied on caregiver or clinician observation rather than objective measurement. Responsiveness and internal consistency were not examined in any included study, so the review cannot tell whether these scales detect change over time or whether their items form a consistent measure. The quality of the psychometric examinations varied, with summary scores from 0.27 to 0.91, and study design was sufficiently described in only six of 14 examinations.

The work was supported by the Academic Collaborative Research Center Healthy Ageing and Intellectual Disabilities, which is financially supported by three Dutch residential care facilities and a university medical centre department. The authors say the funder was not involved in conduct or manuscript preparation, and they declare no conflicts of interest.

Do not assume any listed scale is validated for people with intellectual disabilities taking antipsychotics. No single instrument consistently showed good measurement properties, and four studies had only 2 to 7 participants.