Recurrences during a 10-year follow-up after first renal stone episode.

Each of 92 patients in a Swedish district served by only one hospital had been treated for their first renal stone in 1977 and was evaluated 10 years later. Recurrent stone formation during the observation period was observed in 26% of the patients, with no difference between men and women. Of all the patients who had sought medical advice in 1977 because of urinary stone colic, 51% were experiencing their first stone episode. Ten years later 37% of the original patients were still classified as single stone formers. The recorded recurrence rate was lower than that previously reported in the literature.