From: Fine particulate matter and polycystic ovarian morphology
 | # Cases | HR (95% CI)a | HR (95% CI)b |
---|---|---|---|
PM 2.5 (µg/m3) | |||
 4.90–9.70 | 798 | Reference | Reference |
 9.80–11.30 | 319 | 1.13 (0.88, 1.44) | 1.12 (0.88, 1.43) |
11.40–17.50 | 70 | 0.88 (0.61, 1.25) | 0.89 (0.62, 1.28) |