Review of acute symptomatic urolithiasis in Auckland

To evaluate the incidence of acute symptomatic urolithiasis in the Auckland region. Associated epidemiological factors and stone characteristics were also studied and compared to previous research conducted in order to analyse trends.

All patients that presented acutely with symptomatic urolithiasis to the Auckland District Health Board (AHDB) between July 2014 and June 2015 were studied. Clinical data was obtained from medical records and population data was based on estimates provided by the Ministry of Health. Two-tailed tests and the Pearson Chi-Square tests were used for analysis.

Overall, 1,125 patients (1,328 events) presented with an incidence of 85 per 100,000 per year, which was lower than that reported in 2006. The highest incidence was found among the Middle Eastern ethnic subgroup (0.130 %), followed by Māori (0.102%), Asian (0.087%), European (0.084%) and Pacific (0.041%) ethnicity. Males were more likely to be affected than females. Urolithiasis was most common in the fifth decade of life (25%). Forty-seven percent of the study population presented with multiple stones and 64% had recurrent urolithiasis or were 'high risk' stone formers. Distal ureteric stones <5mm were the most common (27%). Urine cultures were positive in 16% of cases. Seven hundred and thirty-nine (57%) were managed with medical management and ureteroscopy was most commonly performed for those who needed surgical intervention.

The overall incidence of urolithiasis has decreased compared to previous research conducted in Auckland. This deviation could be attributed to the large influx of Asian immigrants observed in this period of time. A caucasian male, between 40-49 years, with a calculus <5mm in the distal ureter with a history of a previous urolithiasis has the highest chance to present with renal colic.