Table 7.

 Subgroup analysis of QALYs by high and low risk subgroups on the Sherbrooke postal questionnaire

Effect	Estimate (95% CI)	P value
Treatment	0.000 (−0.068 to 0.067)	0.989
Sherbrooke	−0.214 (−0.353 to −0.075)	0.003
Treatment*Sherbrooke interaction	0.047 (−0.170 to 0.263)	0.671
Treatment (for low risk Sherbrooke)	0.023 (−0.020 to 0.067)	0.291
Treatment (for high risk Sherbrooke)	0.023 (−0.055 to 0.100)	0.565

Treatment=intervention minus control; Sherbrooke=high minus low; analyses used were analysis of variance and its F tests.