The development and internal consistency of the satisfaction with Antipsychotic Medication Scale.

Background: Satisfaction with antipsychotic medication is an important outcome variable. To date, there is a lack of a well-established measure to quantify patient satisfaction with psychiatric medication. This paper describes the development, dimensionality, reliability and validity of the Satisfaction with Antipsychotic Medication (SWAM) scale.

Method: Clinical and academic experts devised a 33-item Likert scale satisfaction questionnaire. Following a pilot study in a sample of 69 people with schizophrenia, 315 people with schizophrenia on the caseload of local mental health services in three London boroughs completed the questionnaire. The dimensionality, internal consistency and validity of the devised instrument were assessed.

Results: Reliability of the SWAM scale was good for subscales and total scores. The alpha coefficient for the two subscales: treatment acceptability and medication insight were 0.92 and 0.84 respectively. The a coefficient for the SWAM scale total score was 0.91 and ranged from 0.92 to 0.90.

Conclusion: Testing of the psychometric properties of the SWAM scale demonstrate that it is a reliable instrument for measuring patient satisfaction with antipsychotic medication. The measure could be used in routine clinical practice in mental health services to assess patient satisfaction with psychiatric medication.