Table 2. Spring seasonal amplitude of pulmonary TB cases in Wuhan, 2004–2013.

Group		Spring peak/trough month	Seasonal amplitude(%)	SE(%)	95%CI(%) lower	95%CI(%) upper	P value
All PTB cases		Mar/Dec	56.81	6.29	41.93	71.69
Period	Year 2004–2008	Mar/Dec	73.17	5.00	59.29	87.05	0.001§
	Year 2009–2013	Mar/Dec	40.45	4.40	28.24	52.66
Sex	Male	Mar/Dec	58.01	6.18	43.39	72.63	0.831§
	Female	Mar/Dec	55.88	7.65	37.79	73.97
Age(years)	0–14	Apr/Dec	91.05	21.73	39.66	142.44	0.081¶
	15–24	Mar/Dec	74.55	6.14	60.03	89.07
	25–44	Apr/Dec	54.74	6.35	39.72	69.76
	45–64	Mar/Dec	56.52	6.34	41.53	71.51
	65+	May/Dec	66.64	10.52	41.76	91.52
Occupation	Peasant	May/Dec	59.37	9.10	37.85	80.89	0.003¶
	Migrant worker	Apr/Dec	76.10	27.53	10.99	141.21
	Worker	Mar/Dec	64.57	8.28	44.99	84.15
	Student	Mar/Dec	113.22	11.39	86.28	140.16
District	Center	Mar/Dec	54.76	6.10	40.33	69.19	0.702§
	Far	Mar/Dec	58.47	7.34	41.11	75.83
Sputum smear	Positive TB	Mar/Dec	62.22	6.20	47.56	76.88	0.848§
	Negative TB	Mar/Dec	60.22	8.22	40.78	79.66

Abbreviation:SE,standard error; CI,confidence interval.

^§Two-tailed two dependent samples Student's t-test for difference in seasonal amplitudes.

^¶Kruskal-Wallis test for all pairwise multiple comparison among seasonal amplitudes.