Table 2. Incidence of dermatitis herpetiformis.
| Cases | Person-years | Incidence rate (per 100,000 person-years) (95% CI) |
|
||
|---|---|---|---|---|---|
| All | 809 | 65,856,848 | 1.23 | (1.15, 1.32) | Incidence rate ratioa (95% CI) |
| Sex | |||||
| Male | 395 | 32,679,920 | 1.21 | (1.09, 1.33) | 1.00 (ref) |
| Female | 414 | 33,176,929 | 1.25 | (1.13, 1.37) | 0.99 (0.87, 1.14) |
| Age group | |||||
| <5 | 18 | 2,550,088 | 0.71 | (0.42, 1.12) | 1.00 (ref) |
| 5–17 | 47 | 10,140,413 | 0.46 | (0.34, 0.62) | 0.66 (0.39, 1.14) |
| 18–29 | 61 | 8,922,980 | 0.68 | (0.52, 0.88) | 0.97 (0.57, 1.64) |
| 30–49 | 223 | 19,716,119 | 1.13 | (0.99, 1.29) | 1.61 (0.99, 2.59) |
| 50–69 | 311 | 16,041,746 | 1.94 | (1.73, 2.17) | 2.78 (1.73, 4.48) |
| >69 | 149 | 8,485,502 | 1.76 | (1.49, 2.06) | 2.51 (1.54, 4.10) |
| Year | |||||
| 1990 | 18 | 988,225 | 1.82 | (1.08, 2.88) | 0.96 (0.94, 0.97)b |
| 1991 | 24 | 968,428 | 2.48 | (1.59, 3.69) | |
| 1992 | 26 | 1,145,736 | 2.27 | (1.48, 3.33) | |
| 1993 | 21 | 1,302,251 | 1.61 | (1.00, 2.47) | |
| 1994 | 20 | 1,402,018 | 1.43 | (0.87, 2.20) | |
| 1995 | 21 | 1,502,788 | 1.40 | (0.87, 2.14) | |
| 1996 | 29 | 1,707,438 | 1.70 | (1.14, 2.44) | |
| 1997 | 30 | 2,037,465 | 1.47 | (0.99, 2.10) | |
| 1998 | 35 | 2,320,549 | 1.51 | (1.05, 2.10) | |
| 1999 | 47 | 2,732,415 | 1.72 | (1.26, 2.29) | |
| 2000 | 49 | 3,230,521 | 1.52 | (1.12, 2.01) | |
| 2001 | 48 | 3,522,256 | 1.36 | (1.00, 1.81) | |
| 2002 | 52 | 3,773,659 | 1.38 | (1.03, 1.81) | |
| 2003 | 52 | 3,927,535 | 1.32 | (0.99, 1.74) | |
| 2004 | 26 | 4,066,850 | 0.64 | (0.42, 0.94) | |
| 2005 | 50 | 4,184,895 | 1.19 | (0.89, 1.58) | |
| 2006 | 56 | 4,228,443 | 1.32 | (1.00, 1.72) | |
| 2007 | 44 | 4,270,604 | 1.03 | (0.75, 1.38) | |
| 2008 | 43 | 4,269,975 | 1.01 | (0.73, 1.36) | |
| 2009 | 45 | 4,282,448 | 1.05 | (0.77, 1.41) | |
| 2010 | 33 | 4,218,998 | 0.78 | (0.54, 1.10) | |
| 2011 | 33 | 4,127,638 | 0.80 | (0.55, 1.12) | |
| Region | |||||
| North East | 8 | 1,355,821 | 0.59 | (0.25, 1.16) | 1.00 (ref) |
| North West | 108 | 8,425,342 | 1.28 | (1.05, 1.55) | 2.15 (1.05, 4.42) |
| Yorkshire and The Humber | 64 | 2,993,984 | 2.14 | (1.65, 2.73) | 3.37 (1.61, 7.05) |
| East Midlands | 36 | 2,758,331 | 1.31 | (0.91, 1.81) | 2.03 (0.94, 4.38) |
| West Midlands | 71 | 5,786,860 | 1.23 | (0.96, 1.55) | 2.07 (1.00, 4.31) |
| East of England | 74 | 6,441,340 | 1.15 | (0.90, 1.44) | 1.84 (0.88, 3.84) |
| South West | 52 | 4,994,795 | 1.04 | (0.78, 1.37) | 1.69 (0.80, 3.58) |
| South Central | 89 | 7,061,717 | 1.26 | (1.01, 1.55) | 2.22 (1.07, 4.61) |
| London | 75 | 7,183,686 | 1.04 | (0.82, 1.31) | 1.86 (0.89, 3.87) |
| South East Coast | 62 | 5,613,311 | 1.10 | (0.85, 1.42) | 1.88 (0.89, 3.94) |
| Northern Ireland | 27 | 2,292,558 | 1.18 | (0.78, 1.71) | 2.18 (0.98, 4.81) |
| Scotland | 72 | 5,253,856 | 1.37 | (1.07, 1.73) | 2.50 (1.20, 5.20) |
| Wales | 71 | 5,695,248 | 1.25 | (0.97, 1.57) | 2.12 (1.02, 4.41) |
| SES quintile | |||||
| 1 | 153 | 12,297,158 | 1.24 | (1.05, 1.46) | 1.00 (ref) |
| 2 | 144 | 12,531,110 | 1.15 | (0.97, 1.35) | 0.93 (0.74, 1.17) |
| 3 | 180 | 12,874,502 | 1.40 | (1.20, 1.62) | 1.15 (0.92, 1.44) |
| 4 | 164 | 14,983,975 | 1.09 | (0.93, 1.28) | 0.86 (0.69, 1.09) |
| 5 | 168 | 13,170,103 | 1.28 | (1.09, 1.48) | 1.01 (0.81, 1.27) |
Year was included in the model as a continuous variable, as there was no significant departure from a linear trend (likelihood ratio test, P=0.1886).
a
Adjusted for all other variables in the table.
b
Model fitted a linear trend. IRR=1 year increase in calendar time.