Table 3 Modification of the effect of PM_2.5 exposure on respiratory health by temperature or season. The odds ratios and corresponding 95% confidence intervals (CI) with P-values to estimate the increase in risk of healthcare encounter for each 1 µg/m³ increase in PM_2.5 at the given lagged cumulative days or weekly average for each temperature/season combination and 3 respiratory outcomes: (A) asthma, (B) lower respiratory tract infections (LRTI), and (C) upper respiratory tract infections (URTI). For each respiratory condition, the 3 exposure models are presented for PM_2.5, PM_2.5-Temperature (grouped by Colder, Median, and Hotter for display), and PM_2.5-Season (grouped by Fall, Winter, Spring, and Summer). A single critical window was chosen to display based on the main PM_2.5 effect model’s largest odds ratio value. For all lagged windows, see Figs. 3, 4 and 5 and Supplementary Figs. 3, 4, 5, 6, 7, 8, 9, 10 and 11. In addition, bolded values indicate an odds ratio with 95% CI that occurred above the baseline risk of 1.0. n was the sample size for model and group where available, noting that temperature was interacted as a continuous variable and doesn’t define groups

(A) Asthma

 Model

Group

Cumulative Days

Weekly Average

n

Lag

Odds Ratio (CI)

P-val

Lag

Odds Ratio (CI)

P-val

  PM_2.5

–

0–13

1.50 (0.87–2.59)

0.140

7–13

1.92 (1.20–3.06)

0.006

794

  PM_2.5

   -

  Temp

Colder

0–13

2.51 (1.07–5.82)

0.038

7–13

3.23 (1.45–7.18)

0.004

–

Median

0–13

2.03 (1.05–3.89)

0.033

7–13

2.52 (1.39–4.55)

0.002

–

Hotter

0–13

1.30 (0.69–2.42)

0.406

7–13

1.49 (0.86–2.58)

0.153

–

  PM_2.5

   -

  Season

Fall

0–13

0.66 (0.24–1.78)

0.412

7–13

1.45 (0.57–3.64)

0.426

191

Winter

0–13

1.28 (0.29–5.76)

0.744

7–13

3.26 (1.07–9.95)

0.038

247

Spring

0–13

1.25 (0.26–5.88)

0.772

7–13

1.29 (0.33–4.97)

0.709

190

Summer

0–13

2.00 (0.67–5.94)

0.214

7–13

1.57 (0.60–4.06)

0.357

166

(B) LRTI

 Model

Group

Cumulative Days

Weekly Average

n

Lag

Odds Ratio (CI)

P-val

Lag

Odds Ratio (CI)

P-val

  PM_2.5

–

0–12

2.42 (1.13–5.20)

0.022

6–12

2.36 (1.28–4.32)

0.006

638

  PM_2.5

   -

  Temp

Colder

0–12

2.09 (0.81–5.32)

0.123

6–12

2.82 (1.23–6.48)

0.014

–

Median

0–12

2.33 (1.06–5.12)

0.034

6–12

2.55 (1.35–4.81)

0.004

–

Hotter

0–12

2.94 (0.91–9.50)

0.070

6–12

2.06 (0.72–5.82)

0.175

–

  PM_2.5

   -

  Season

Fall

0–12

1.46 (0.18–11.4)

0.716

6–12

3.02 (0.52–17.4)

0.218

61*

Winter

0–12

1.36 (0.36–5.09)

0.646

6–12

1.49 (0.60–3.68)

0.389

374

Spring

0–12

1.65 (0.27–9.81)

0.579

6–12

3.74 (0.87–16.1)

0.076

169

Summer

0–12

1.89 (0.06–63.6)

0.723

6–12

0.05 (0.00–3.56)

0.172

34*

(C) URTI

 Model

Group

Cumulative Days

Weekly Average

n

Lag

Odds Ratio (CI)

P-val

Lag

Odds Ratio (CI)

P-val

  PM_2.5

–

0–13

1.37 (1.12–1.65)

0.001

4–10

1.32 (1.12–1.55)

 < 0.001

8,392

  PM_2.5

   -

  Temp

Colder

0–13

1.10 (0.86–1.40)

0.435

4–10

1.22 (0.98–1.52)

0.075

–

Median

0–13

1.30 (1.06–1.59)

0.010

4–10

1.27 (1.07–1.50)

0.005

–

Hotter

0–13

1.84 (1.41–2.41)

 < 0.001

4–10

1.38 (1.08–1.77)

0.009

–

  PM_2.5

   -

  Season

Fall

0–13

0.69 (0.46–1.00)

0.053

4–10

0.85 (0.59–1.19)

0.345

1,266

Winter

0–13

1.22 (0.86–1.74)

0.259

4–10

1.10 (0.84–1.44)

0.467

4,224

Spring

0–13

3.06 (1.89–4.95)

 < 0.001

4–10

3.28 (2.18–4.91)

 < 0.001

2,254

Summer

0–13

3.35 (1.85–6.04)

 < 0.001

4–10

1.38 (0.85–2.22)

0.191

648