|
Risk factor
|
Controls
|
NP+ve cases
|
NP-ve cases
|
|---|
| |
n
|
n
|
ORa
|
(95% CI)
|
n
|
ORa
|
(95% CI)
|
|---|
|
BMI (Kg/m
2
)
| | | | | | | |
|
<25
|
303
|
118
|
1
| |
154
|
1
| |
|
≥25 and <30
|
254
|
162
|
1.6
|
(1.2-2.2)
|
151
|
1.2
|
(0.9-1.6)
|
|
≥30
|
220
|
184
|
2.3
|
(1.7-3.1)
|
93
|
0.9
|
(0.7-1.2)
|
|
Missing
|
22
|
11
|
1.2
|
(0.5-2.6)
|
11
|
0.9
|
(0.4-1.9)
|
|
Smoking habits
| | | | | | | |
|
Never smoked
|
367
|
251
|
1
| |
209
|
1
| |
|
Ex-smoker
|
210
|
136
|
1.1
|
(0.8-1.4)
|
97
|
0.9
|
(0.7-1.2)
|
|
Current smoker
|
213
|
83
|
0.6
|
(0.5-0.8)
|
101
|
0.8
|
(0.6-1.1)
|
|
Missing
|
9
|
5
|
0.6
|
(0.2-2.3)
|
2
|
0.4
|
(0.1-2.0)
|
|
Other disease
b
| | | | | | | |
|
Diabetes
|
56
|
37
|
1.1
|
(0.7-1.7)
|
18
|
0.7
|
(0.4-1.2)
|
|
Rheumatoid arthritis
|
32
|
23
|
1.3
|
(0.8-2.3)
|
19
|
1.3
|
(0.7-2.3)
|
|
Other arthritis
|
169
|
92
|
1.0
|
(0.8-1.4)
|
92
|
1.3
|
(1.0-1.8)
|
|
Mental health
| | | | | | | |
|
Good
|
333
|
170
|
1
| |
157
|
1
| |
|
Intermediate
|
236
|
155
|
1.2
|
(0.9-1.7)
|
142
|
1.4
|
(1.0-1.8)
|
|
Poor
|
225
|
148
|
1.3
|
(1.0-1.8)
|
108
|
1.1
|
(0.8-1.5)
|
|
Missing
|
5
|
2
|
0.5
|
(0.1-3.7)
|
2
|
0.9
|
(0.2-4.8)
|
|
Number of somatic symptoms at least moderately distressing in past week
| | | | | | | |
|
0
|
234
|
130
|
1
| |
93
|
1
| |
|
1
|
193
|
123
|
1.1
|
(0.8-1.6)
|
110
|
1.5
|
(1.1-2.1)
|
|
≥2
|
372
|
222
|
1.1
|
(0.8-1.4)
|
206
|
1.5
|
(1.1-2.0)
|
-
aAdjusted for sex and age (in 10-year strata) and ethnicity.
-
bRisk estimates are for those with the disease relative to those who did not have it.
