Table 3. Relationship between number of ranibizumab injections and letter gains in year 1 (a) and over 2 years (b) tested by regression analysis using optical coherence tomography and ophthalmoscopy as an instrumental variable (all countries).

	Coefficient	SE	Lower 95% CI	Upper 95% CI	P-valuea
(a)
Number of injections (ranibizumab)	5.409	1.514	2.441	8.377	<0.001
Age at start of therapy	–0.106	0.081	–0.265	0.052	0.188
VAS at baseline	–0.279	0.037	–0.352	–0.206	<0.001
Constant	–3.760	14.380	-–31.945	24.426	0.794

(b)	Coefficient	SE	Lower 95% CI	Upper 95% CI	P-valueb
Number of injections (ranibizumab)	1.933	0.552	0.852	3.015	<0.001
Age at start of therapy	–0.177	0.081	–0.335	–0.018	0.029
VAS at baseline	–0.391	0.035	–0.459	–0.322	<0.001
Constant	19.953	10.461	–0.550	40.455	0.056

Abbreviation: VAS, visual acuity score.

^aTwo-stage least-squares test: number of observations of the analysis was 1342, F-value: 16.57 (first-stage analysis), R²=0.0358.

^bTwo-stage least-squares test: number of observations of the analysis was 980, F-value: 19.68 (first-stage analysis), R²=0.057.