Table 3.

Effect of mail-outs and mail-outs plus phone calls compared with usual care on completion of cardiac rehabilitation and adherence to medication at 12 months after myocardial infarction based on 2632 patients

Primary outcome and intervention*	Odds ratio (95% CI)	P value†
Cardiac rehabilitation completion (yes/no):
Mail-outs (n=878)	1.19 (0.95 to 1.50)	0.34
Mail-outs plus phone calls (n=878)	1.55 (1.18 to 2.03)	0.007
Medication adherence (number of drug classes with no days missed in past 7 days; 0-4):
Mail-outs‡ (n=878)	0.98 (0.81 to 1.19)	0.98
Mail-outs plus phone calls‡ (n=878)	0.99 (0.82 to 1.20)	0.98

All odds ratios are adjusted for fixed effect of centre (stratifying factor in randomisation). Fully conditional specification was used to create 20 imputed datasets for each outcome (that is, multiple imputation). These multiple datasets were then analysed independently using regression analysis. The effect estimates and 95% confidence intervals presented were obtained by pooling regression results across the imputed datasets using Rubin’s rules (see statistical appendix for more details).

^*Reference group is usual care (n=876).

^†Adjusted for multiple comparisons and multiple primary outcomes using step-down Šidák procedure.

^‡Assumes proportionality of effect across all four logits (4 v <4, ≥3 v <3, ≥2 v <2, ≥1 v 0).