Content validity and test-retest reliability of a low back pain questionnaire in Zimbabwean adolescents

Table 3 Test-retest reliability results for questions eliciting numerical responses

		Test	Retest
Item number	Item description	Mean (SD)	Mean (SD)	t-value	P value	ICC	95% CI	SEM
Q2	Mean age of onset of LBP	13.4 (1.96)	13.5 (1.93)	-1.40	0.17	0.87	0.81-0.91	1.36
Q6	Mean intensity for recurrent LBP on VAS	2.59 (1.27)	2.63 (1.30)	-1.00	0.32	0.97	0.94-0.98	0.44
Q9	Mean intensity for ‘point’LBP	2.15 (1.21)	2.69 (1.31)	-1.85	0.09	0.62	0.15-0.86	1.42

Q question, SD standard deviation, ICC Intraclass correlation coefficient, SEM standard error of measurement, CI confidence interval, VAS Visual Analogue Scale, ‘point’=LBP at the point of collecting data

ISSN: 2057-0082