Circadian pattern in occurrence of renal colic in an emergency department: analysis of patients' notes

According to anecdotal evidence people are more at risk of renal colic during the night. Although this has never been investigated, several studies have shown a circadian variation for other acute diseases.1 We investigated whether renal colic occurred in a circadian pattern. We reviewed all episodes of renal colic from 1 January 1990 to 31 December 1996 in the emergency department of St Anna Hospital, which serves the 150 000 people in the city and suburbs of Ferrara, Italy. Altogether 3410 episodes of renal colic were reported (66.0% (2281) in men). The mean age of the patients was 46 years (SD 16 years). The time (within 30 minutes) when symptoms started could be determined for 3360 (98.5%) patients (2272 men and 1088 women). All patients were physically examined and had …