Development of the Japanese Core Outcome Measures Index (COMI): cross-cultural adaptation and psychometric validation

Table 4 Correlations^a between the COMI and the related questionnaires and domains

	COMI
	Pain	Function	Symptom-specific well-being	QOL	Disability	Summary
EQ-5D Summary index	−0.60	−0.58	−0.54	− 0.60	− 0.48	− 0.72
RDQ	0.64	0.63	0.52	0.52	0.54	0.71
SF-8 PCS	−0.55	−0.62	−0.48	− 0.50	−0.43	− 0.66
SF-8 MCS	−0.36	− 0.46	−0.33	− 0.54	−0.34	− 0.52
STarT Total	0.63	0.60	0.53	0.57	0.48	0.71
STarT Sub score (psychological)	0.56	0.56	0.50	0.55	0.43	0.67

All the correlations were significant (P < 0.001)
^aSpearman Rank correlation coefficients
COMI: Core Outcome Measures Index; QOL: quality of life; EQ-5D: the EuroQol 5 Dimension; RDQ: Roland Morris Disability Questionnaire; SF-8: Short Form 8™ Health Survey; PCS: physical component summary; MCS: mental component summary; STarT: the Keele STarT Back Screening Tool