Table 2. Comparison of participant characteristics by birth season (summer vs. winter).

Variable		Birth season		OR	95% CI	p-value
		Summer	Winter
Number of patients		189	204
Age (y)		60.5±10.0	62.2±11.1			0.100
Digit ratio		0.951±0.040	0.941±0.040			0.014
PV (mL)		33.4±14.9	38.2±20.7			0.008
PSA (ng/mL)		4.59±15.54	3.94±9.44			0.617
PSAD (ng/mL/mL)		0.129±0.473	0.096±0.234			0.375
Biopsy (%)		17.5 (33/189)	24.0 (49/204)			0.109
Cancer (%)		5.3 (10/189)	11.3 (23/204)			0.031
Detection (%)		30.3 (10/33)	46.9 (23/49)			0.130
Biopsy
	No	156	155	1.494	0.912–2.450	0.110
	Yes	33	49
Cancer
	No	179	181	2.275	1.053–4.916	0.033
	Yes	10	23
Detection
	No	23	26	2.035	0.802–5.160	0.132
	Yes	10	23

Values are presented as number only or mean±standard deviation.

PV, prostate volume; PSA, prostate-specific antigen; PSAD, PSA density; OR, odds ratio; CI, confidence interval.

According to the definition of the solar season, the birth seasons were set as follows. Summer: May, June, and July and winter: November, December, and January.

Student’s t-test and chi-squared test were used.