Reliability of the Dutch Version of the Matson Evaluation of Drug Side Effects in People With Intellectual Disabilities.

BACKGROUND

People with intellectual disabilities often use psychotropic medications. Recognising side effects in this population can be challenging while they can negatively impact the quality of life. An accurate screening instrument is crucial to identify side effects of psychotropic medication in people with intellectual disabilities. For this purpose, the Matson Evaluation of Drug Side Effects (MEDS) is the most reliable and well-researched instrument. We translated the MEDS into Dutch, considering that the Dutch version of the MEDS must be accurate and aligned with its intended meaning, avoiding multiple interpretations; this study aimed to assess its intrarater and interrater reliabilities in people with intellectual disabilities using psychotropic medication.

METHODS

A certified medical translation agency performed translation and back-translation of the MEDS. Two researchers administered the MEDS three times on the same day. Participants were people with intellectual disabilities using psychotropic medication. Demographic and medical data were collected via questionnaires. Scoring and calculation of total domain scores, severity domain scores, duration domain scores and composite scale scores followed the MEDS manual. Intraclass correlation coefficients (ICC) and 95% confidence intervals of these scores were used to assess intrarater and interrater reliabilities.

RESULTS

The study sample included 40 adults with intellectual disabilities. Intrarater reliability was good to excellent for total domain scores (ICCs ranging from 0.873 to 1.000) and excellent for the total composite scale score (ICC = 0.945). Interrater reliability was moderate to excellent for total domain scores (ICCs ranging from 0.713 to 0.922) and good for the total composite scale score (ICC = 0.894).

CONCLUSIONS

This study demonstrated moderate to excellent intrarater and interrater reliabilities for the Dutch version of the MEDS. This confirms its potential as a valuable instrument for clinicians to identify and monitor side effects in people with intellectual disabilities using psychotropic medication. We recommend the use of the Dutch version of the MEDS in both Dutch clinical practice and research for this purpose.