Table 2. The relationship between PC and SD.

Authors (year)	Measures	Design	Parameters	Subjects	Criteria	Main findings
Zhao et al. (52) (in 2014)	Transabdominal ultrasonography	Prospective cohort study	CPSI, IIEF-15, 5-item Premature Ejaculation Diagnostic Tool scales	PC (n=175); no PC (n=183)	Patients were diagnosedwith CP/CPPS according to the NIH criteria	PC were significantly associated with the presence of ED in CP/CPPS men
Cho et al. (53) (in 2016)	TRUS	Prospective cohort study	IPSS, IIEF-5, PSA, BMI, PV	Group A (n=267, no or small PC); group B (n=79, large PC)	Patients who underwent TRUS for a routine check-up prostate with aged 40 years or older were enrolled, and the prostatic calcification grading and prostate volume were checked by TRUS	Large PC and old age may worsen ED
Fei et al. (37) (in 2017)	TRUS	Prospective cohort study	NIH-CPSI, IPSS, IIEF-5, white blood cell counts	PC (n=121); no PC (n=151)	Young males with CP/CPPS	The study did not reveal the association of ED of patients with and without calcifications

BMI, body mass index; CP/CPPS, chronic prostatitis/chronic pelvic pain syndrome; CPSI, chronic prostatitis symptom index; ED, erectile dysfunction; IIEF-15/5, international index of Erectile Function-15/5 items; IPSS, International Prostate Symptom Score; NIH, the National Institutes of Health; NIH-CPSI, National Institutes of Health Chronic Prostatitis Symptom Index; PC, prostatic calculi; PV, prostate volume; PSA, prostate-specific antigen; SD, sexual dysfunction; TRUS, transrectal ultrasonography.