Long-term effects of flooding on mortality in England and Wales, 1994-2005: controlled interrupted time-series analysis

Table 3 Observed and expected number of deaths in flooded areas by four week periods from the date of onset of flooding

Weeks from date of onset of flood	Observed deaths (O)	Expected deaths (E)	O/E ratio (95%CI)	Ratio of deaths^a
Year before flood
-52 to -49	72	59.25	1.22 (0.95 - 1.53)	-
-48 to -45	79	63.40	1.25 (0.99 - 1.55)	-
-44 to -41	66	62.76	1.05 (0.81 - 1.34)	-
-40 to -37	60	57.48	1.04 (0.80 - 1.34)	-
-36 to -33	58	54.33	1.07 (0.81 - 1.38)	-
-32 to -29	57	53.38	1.07 (0.81 - 1.38)	-
-28 to -25	46	53.42	0.86 (0.63 - 1.15)	-
-24 to -21	56	53.80	1.04 (0.79 - 1.35)	-
-20 to -17	64	53.61	1.19 (0.92 - 1.52)	-
-16 to -13	51	53.06	0.96 (0.72 - 1.26)	-
-12 to -9	61	53.53	1.14 (0.87 - 1.46)	-
-8 to -5	45	54.69	0.82 (0.60 - 1.10)	-
-4 to -1^b	53	56.84	0.93 (0.70 - 1.22)	-
Pre-flood total (weeks -52 to -1) ^c	768	729.55	1.05 (0.98 - 1.13)	1.00
Year after flood
Day of flood	2	2.05	0.98 (0.12 - 3.53)	0.93
1 to 4 ^c	62	57.73	1.07 (0.82 - 1.38)	1.02
5 to 8	59	58.11	1.02 (0.77 - 1.31)	0.96
9 to 12	50	58.60	0.85 (0.63 - 1.12)	0.81
13 to 16	58	57.28	1.01 (0.77 - 1.31)	0.96
17 to 20	57	55.87	1.02 (0.77 - 1.32)	0.97
21 to 24	59	54.34	1.09 (0.83 - 1.40)	1.03
25 to 28	43	53.34	0.81 (0.58 - 1.09)	0.77
29 to 32	47	53.19	0.88 (0.65 - 1.18)	0.84
33 to 36	52	54.08	0.96 (0.72 - 1.26)	0.91
37 to 40	54	55.53	0.97 (0.73 - 1.27)	0.92
41 to 44	57	56.89	1.00 (0.76 - 1.30)	0.95
45 to 48	38	56.19	0.68 (0.48 - 0.93)	0.64
49 to 52	54	56.17	0.96 (0.72 - 1.25)	0.91
Post-flood total (weeks 0 to 52) ^c	692	729.36	0.95 (0.88 - 1.02)	0.90

^a Ratio of deaths in post-flood periods compared with average for the preceding year.
^b Week 1 begins on the day after the flood, i.e. T_{0+1 day}
^c The numbers of total observed deaths differ slightly from those in Table 1 because the four-week block include an additional day either side of the date of onset of the flood.

ISSN: 1476-069X