Table 5. Overall risk of appendicitis during various reference time intervals associated with increases in the interquartile range of PM₁₀, stratified by age groups

Lag days	Age (yr)
	<10	10–20	20–29	30–39	40–49	50–59	≥60
0–1	1.129 (1.016–1.255)	1.013 (0.943–1.089)	1.013 (0.936–1.096)	0.998 (0.929–1.072)	0.985 (0.891–1.088)	1.063 (0.964–1.171)	1.069 (0.946–1.207)
0–2	1.130 (1.023–1.248)	1.022 (0.949–1.100)	1.022 (0.942–1.109)	1.001 (0.921–1.087)	1.020 (0.915–1.138)	1.066 (0.954–1.190)	1.043 (0.924–1.178)
0–3	1.140 (1.033–1.258)	1.032 (0.951–1.121)	1.003 (0.921–1.093)	1.013 (0.926–1.109)	1.054 (0.937–1.184)	1.056 (0.939–1.188)	1.046 (0.914–1.198)
0–4	1.169 (1.054–1.297)	1.038 (0.953–1.129)	1.008 (0.927–1.095)	1.027 (0.936–1.126)	1.065 (0.944–1.202)	1.034 (0.920–1.162)	1.056 (0.927–1.203)
0–5	1.201 (1.074–1.342)	1.044 (0.955–1.142)	1.012 (0.927–1.106)	1.045 (0.950–1.149)	1.084 (0.955–1.232)	1.017 (0.897–1.152)	1.760 (0.938–1.234)
0–6	1.227 (1.090–1.382)	1.046 (0.948–1.153)	1.016 (0.924–1.118)	1.031 (0.928–1.145)	1.082 (0.954–1.228)	1.005 (0.879–1.148)	1.109 (0.956–1.287)
0–7	1.235 (1.087–1.402)	1.021 (0.919–1.135)	0.991 (0.891–1.101)	1.024 (0.914–1.148)	1.073 (0.936–1.231)	0.993 (0.859–1.149)	1.122 (0.955–1.318)
0–8	1.233 (1.076–1.414)	1.007 (0.899–1.128)	0.972 (0.867–1.090)	1.011 (0.897–1.141)	1.050 (0.908–1.214)	0.997 (0.853–1.165)	1.132 (0.953–1.346)
0–9	1.245 (1.074–1.444)	1.026 (0.908–1.160)	0.964 (0.853–1.090)	0.998 (0.878–1.136)	1.033 (0.886–1.206)	0.982 (0.831–1.160)	1.156 (0.961–1.391)
0–10	1.238 (1.055–1.452)	1.014 (0.890–1.155)	0.947 (0.830–1.080)	0.988 (0.861–1.134)	1.023 (0.869–1.204)	0.979 (0.819–1.170)	1.157 (0.945–1.417)
0–11	1.192 (1.005–1.414)	0.998 (0.869–1.146)	0.915 (0.797–1.050)	0.994 (0.856–1.154)	1.011 (0.848–1.204)	1.003 (0.831–1.211)	1.150 (0.925–1.429)
0–12	1.131 (0.944–1.357)	0.962 (0.831–1.112)	0.879 (0.760–1.017)	0.970 (0.829–1.134)	0.991 (0.823–1.194)	1.031 (0.844–1.259)	1.122 (0.891–1.414)
0–13	1.085 (0.892–1.320)	0.929 (0.795–1.084)	0.866 (0.740–1.013)	0.937 (0.793–1.107)	0.969 (0.798–1.177)	1.058 (0.857–1.308)	1.105 (0.864–1.415)
0–14	1.042 (0.846–1.282)	0.897 (0.762–1.056)	0.839 (0.709–0.993)	0.900 (0.753–1.075)	0.940 (0.766–1.153)	1.053 (0.841–1.319)	1.111 (0.851–1.149)

All models were adjusted for daily mean temperature and humidity.
PM₁₀, particulate matter ≤10 μm in diameter.