TABLE 3.

Correlation between clipping and primary outcome measures

Model	1-Yr Mortality*		30-Day Mortality*		Mortality†
	OR (95% CI)	p Value	OR (95% CI)	p Value	HR (95% CI)	p Value
Crude	0.76 (0.63–0.92)	0.005	0.86 (0.64–1.17)	0.338	0.77 (0.64–0.93)	0.005
Multivariable regression‡	1.05 (0.86–1.29)	0.630	1.26 (0.91–1.74)	0.156	1.05 (0.87–1.27)	0.621
Propensity score adjustment‡	1.04 (0.86–1.28)	0.654	1.28 (0.93–1.76)	0.135	1.05 (0.87–1.28)	0.602
IPW‡	0.98 (0.84–1.13)	0.739	1.18 (0.93–1.50)	0.174	0.99 (0.87–1.14)	0.960
IV analysis§	1.26 (0.68–2.31)	0.461	1.65 (0.68–3.96)	0.260	1.28 (0.58–2.85)	0.538

^*Analyses based on logistic regression.

^†Time to event; analyses based on a Cox proportional-hazards model (limited to 1-year follow-up).

^‡Mixed effects; includes patient’s HRR as a random effect variable.

^§Hospital referral region coiling rate (fraction of coiling of total procedures performed) was used as an instrument of choice of treatment.