The translation and validation of the Japanese version of the patient assessment of constipation quality of life scale.
OBJECTIVE
The aim of the present study was to conduct a psychometric evaluation of the patient assessment of constipation quality of life scale (PAC-QOL) in the Japanese language.


METHODS
The PAC-QOL was translated into Japanese. After being linguistically validated, the Japanese version of the PAC-QOL was administered to a sample of 121 patients. Validation studies were conducted to evaluate the internal consistency reliability (Cronbach's alpha), reproducibility [intraclass correlation coefficients (ICCs)], the convergent validity (correlated with the Short-Forum 36 Health Survey), the discriminant validity [correlated with the constipation scoring system (CSS)], the cross-sectional validity (analysis of variance models), and responsiveness (effect size) of the PAC-QOL scales.


RESULTS
The internal consistency was good for all of the scales (Cronbach's alpha coefficient >0.7) and reproducible (ICCs >0.7). The four scales of the PAC-QOL were significantly correlated with the Short-Forum 36 Health Survey (P < 0.01 except for the satisfaction subscale) and the CSS scores (P < 0.01 except for the satisfaction subscale). The PAC-QOL scale scores were significantly associated with constipation severity (P < 0.05). The effect size in patients reporting improvements in constipation over the treatment period was moderate to large, with a subscale effect size ranging from 0.69 to 1.18 and an overall scale effect size of 1.12. Similar findings were observed in the original validation study.


CONCLUSIONS
The linguistic and psychometric evaluation demonstrated the validity of the Japanese version of the PAC-QOL.
Department of Gastroenterological Surgery, Kameda Medical Center, 929 Higashicho, Kamogawa City, Chiba, 296-8602, Japan. tsunoda.akira@kameda.jp.
Akira
A
Tsunoda
Department of Surgery, Coloproctology Center, Takano Hospital, Kumamoto, Japan.
Kazutaka
K
Yamada
Department of Surgery, Coloproctology Center, Takano Hospital, Kumamoto, Japan.
Masahiro
M
Takano
Department of Gastroenterological Surgery, Kameda Medical Center, 929 Higashicho, Kamogawa City, Chiba, 296-8602, Japan.
Hiroshi
H
Kusanagi
D002908:Chronic Disease; D003248:Constipation / Q000523:psychology*; D003430:Cross-Sectional Studies; D006801:Humans; D007564:Japan; D007802:Language; D010361:Patients / Q000523:psychology*; D011594:Psychometrics / Q000379:methods*; D011788:Quality of Life / Q000523:psychology*; D012720:Severity of Illness Index; D014177:Translations
Constipation; Quality of life; Validation study