SOPI is designed for use in questionnaire-based surveys and for outcome evaluation in research and clinical contexts.
It is particularly suited for epidemiological studies and intervention research in which occupational participation is treated as a quantitative outcome.
Conceptual Structure
SOPI consists of nine items covering:
Three occupational domains: leisure, productivity, and self-care
Three dimensions: control, balance, and satisfaction
This structure is derived from the concept of occupational performance in the Canadian Model of Occupational Performance (CMOP).
Administration
1. Target population
SOPI has been applied to community-dwelling middle-aged and older adults, university students, and individuals receiving rehabilitation services.
As SOPI assesses occupational participation (occupational performance), it is theoretically applicable across diverse populations.
2. Format
A self-completed questionnaire consisting of nine items.
3. Instructions
Respondents are asked to reflect on meaningful activities in their daily lives and rate their current level of participation.
4. Mode of administration
SOPI is primarily administered as a self-completed questionnaire and can be used in questionnaire-based surveys, including postal surveys.
It can also be administered through interviews when necessary.
Scoring
Each item is rated on a five-point scale:
5 = Very satisfied
4 = Fairly satisfied
3 = Somewhat satisfied
2 = Not very satisfied
1 = Not satisfied
Scores are calculated using a simple summation method:
Total score (SOPI score): 9–45
Domain scores (3–15): leisure, productivity, and self-care
Dimension scores (3-15): control, balance, and satisfaction
Domain scores have demonstrated internal consistency and relative independence in the original study.
In contrast, dimension scores should be interpreted with caution, as correlations among dimensions may be relatively high, suggesting limited independence. However, dimension scores may be used for exploratory or descriptive purposes.
A transformed scoring method scaled to 100 points was introduced in the original study. However, the raw score method is generally sufficient and recommended for most research and clinical purposes.
Interpretation
SOPI scores reflect the extent to which individuals are able to engage in meaningful activities with a sense of control, balance, and satisfaction.
Changes in scores can be used to evaluate intervention effects or to examine differences between groups in research settings.
Notes on Use
SOPI does not specify particular activities; respondents are asked to imagine activities that are meaningful to them.
This approach allows the measure to reflect individual differences while maintaining comparability across participants.
Changes to the layout or presentation of the questionnaire may affect response patterns and measurement outcomes. Therefore, the original format should be maintained whenever possible.