Effectiveness of the 23-valent polysaccharide pneumococcal vaccine against invasive pneumococcal disease in people 60 years or older

Table 3 Vaccination histories in cases and control subjects, unadjusted and adjusted Odds Ratios, and estimates of effectiveness of pneumococcal vaccination against overall invasive pneumococcal disease (IPD) and IPD by vaccine types.

			Unadjusted analysis		Adjusted analysis
Type of infection	No. of subjects	No. (%) of vaccinated	OR^a (95% CI)	Effectiveness of vaccination % (95% CI)	OR^b (95% CI)	Effectiveness of vaccination % (95% CI)
IPD by vaccine types					^(c)
Case patients	48	15 (31.3)	0.28 (0.11-0.67)	72% (33-89)	0.23 (0.08-0.60)	77% (40-92)
Control subjects	96	52 (54.2)	p = 0.005		p = 0.003
Overall IPD					^(d)
Case patients	88	34 (38.6)	0.34 (0.18-0.63)	66% (37-82)	0.28 (0.15-0.54)	72% (46-85)
Control subjects	176	104 (59.1)	p = 0.001		p < 0.001

NOTE: OR, odds ratio of vaccination versus no vaccination in cases and controls; Vaccine effectiveness = (1 - matched OR for vaccination)*100%; CI, confidence interval.
^aMantel-Haenszel matched Odds Ratio.
^bMatched, adjusted Odds Ratio by conditional logistic regression model.
^cAdjusted for age, smoking and stroke.
^dAdjusted for age, chronic heart disease, alcoholism and smoking.

ISSN: 1471-2334