Negative binomial regression models revealed strong statistical evidence for annual oscillation for both pneumococcal disease and combined influenza A and B infections (p for nonlinear combination of sine and cosine oscillators for both pathogens ,0.001). Whereas meta-analyses revealed substantial heterogeneity of phase (Cochran Q statistic: x 2 = 62810.15, df = 15, p,0.001; I 2 = 100.0%) and amplitude (Cochran Q statistic: x 2 = 5752.86, df = 15, p,0.001; I 2 = 99.7%) terms for influenza A and B (combined), there was less heterogeneity of amplitude (Cochran Q statistic: x 2 = 40.06, df = 15, p,0.001; I 2 = 62.6%) terms for S. pneumoniae, and no significant heterogeneity for phase (Cochran Q statistic: x 2 = 23.28, df = 15, p = 0.08; I 2 = 35.6%) terms. Differences in heterogeneity x 2 statistics between pathogens [12] were highly significant for both amplitude and phase terms (p,0.001). Heterogeneity of phase and amplitude terms of influenza A and influenza B was in line with influenza A and B (combined) (unpublished data). Findings were robust when outlier seasons (2003-2004 and 2008-2009 ) were excluded in sensitivity analyses. Accordingly, no significant association between amplitude and phase of oscillatory waves of pneumococcal disease and influenza A and B (combined), influenza A, or influenza B could be detected using Spearman correlation (Tables 1-3 ).