Table 3.

Spearman's ranked correlation between Rockwood frailty index and pre- and post-vaccination HAI titres.

		Spearman's correlation			Pearson's correlation
Strain	HAI responses	ρ	p	p.adj	r	p	p.adj
A/H1N1	Pre-vaccination (Day 0) HAI titer	0.0535	0.446	1	0.0197	0.780	1
	Post-vaccination (Day 28) HAI titer	0.0235	0.738	1	−0.0075	0.915	1
	Post/Pre-vaccination HAI ratio	−0.0290	0.680	1	−0.0263	0.708	1
A/H3N2	Pre-vaccination (Day 0) HAI titer	0.0995	0.156	1	0.0501	0.475	1
	Post-vaccination (Day 28) HAI titer	0.0137	0.846	1	−0.0622	0.375	1
	Post/Pre-vaccination HAI ratio	−0.0565	0.421	1	−0.1000	0.154	1
B	Pre-vaccination (Day 0) HAI titer	0.0239	0.734	1	0.0579	0.4095	1
	Post-vaccination (Day 28) HAI titer	−0.0423	0.547	1	−0.1170	0.0947	0.853
	Post/Pre-vaccination HAI ratio	−0.1076	0.125	1	−0.1390	0.0468	0.468

The correlations were performed using log₂ transformed titer values.