Renal stone disease in Christchurch, New Zealand. Part 2: a community study on the burden of renal stone disease.

Aim: To quantify the annual burden of a 12-month cohort of newly diagnosed renal stones in the defined community of Christchurch, New Zealand, and to assess this burden by stone size and position.

Method: In this prospective study of stone burden, patients in the Christchurch region of New Zealand with newly diagnosed renal stones maintained a weekly diary for a 12-month period to record the utilisation of health services and financial and social costs to families and partners. Patient records were matched with diagnostic and clinical information to provide a comprehensive database. The economic costs of the various services were estimated.

Results: From November 2001 to November 2002, 422 newly diagnosed renal stones were detected--an annual incidence of 105 per 100,000 population. The annual mean cost of these stones was NZ$4274 per person in the first 12 months. The greatest costs were those for emergency visits, hospitalisations and for operative procedures (23.8%, 22.7%, and 21.8% of total financial burden respectively). Patient workdays lost accounted for 10.9% of total costs. Ureteric stones caused greater social burden than kidney stones. Costs were influenced by stone location and size, being significantly higher for ureteric stones and for larger stones.

Conclusions: Renal stone disease places a considerable burden on the community. The main burdens were related to health service costs, with personal and pharmaceutical costs representing only a small component. The financial burden to society is estimated at $450,000 per 100,000 population ($NZ in 2001/02).