The Japanese version of the Sleep Problem Acceptance Questionnaire (SPAQ-J) is 'a valid and partially reliable measure of psychological flexibility related to sleep problems in the Japanese population.'
The SPAQ-J retained the two-factor structure of the original English version, confirmed by confirmatory factor analysis.
Internal consistency of the SPAQ-J was adequate for both subscales.
Test-retest reliability for both SPAQ-J subscales fell below the recommended threshold.
The Willingness subscale showed moderate correlations with all concurrent validity scales, while Activity Engagement showed moderate-to-weak correlations.
Adding SPAQ-J subscales to hierarchical multiple regression models significantly enhanced explanatory power for insomnia-related outcomes.
Measurement invariance of the SPAQ-J was demonstrated across sex and age groups.
This research suggests that a Japanese-language version of the Sleep Problem Acceptance Questionnaire (SPAQ-J) can be used to measure how well people with insomnia psychologically accept their sleep difficulties, rather than fighting or avoiding them. The questionnaire measures two aspects of this acceptance: whether people continue engaging in meaningful daily activities despite poor sleep (Activity Engagement), and whether they are willing to experience sleep problems without excessive struggle (Willingness). The study tested the questionnaire in 861 Japanese adults with insomnia and found that its structure, internal consistency, and ability to measure what it claims to measure were all satisfactory. However, the study also found a limitation: when the same individuals completed the questionnaire twice over a period of time, their scores were not as consistent as recommended standards require, meaning the questionnaire's stability over time was lower than ideal. This suggests the SPAQ-J may be more useful as a snapshot measure rather than for tracking change in individuals over time. Despite this, the questionnaire added meaningful explanatory power when predicting insomnia-related outcomes, and performed consistently across different sexes and age groups. This research matters because psychological flexibility — the ability to accept difficult experiences like poor sleep rather than letting them dominate one's life — is a key target in modern behavioral treatments for insomnia. Having a validated Japanese-language tool to measure this concept could support both clinical practice and research on insomnia treatment in Japan, particularly approaches like Acceptance and Commitment Therapy (ACT).
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Upload Your LabsBando M, Asakura T, Sato H, Okajima I. (2026). Reliability and validity of the Japanese version of the Sleep Problem Acceptance Questionnaire.. PloS one. https://doi.org/10.1371/journal.pone.0358990