William G Robertson

Institute of Urology and Nephrology, Royal Free and University College Medical School, University College London, 48 Riding House Street, London W1W 7EY, United Kingdom

FIGURES

Figure 1. The smoothed frequency distributions of the urinary risk factors for calcium- and uric acid-containing stone-formation in 600 idiopathic stones-formers (SF) and 250 normal controls (N).

Figure 2. A: The frequency distributions of urinary calcium excretion in stone-formers (SF) and normal subjects (N) taken from Figure 1. B: The derivation of the "risk curve" for calcium (aCa) calculated from the ratio of SF/N at each level of urinary calcium.

Figure 3. The "risk curves" for the various risk factors for calcium- and uric acid-containing stones calculated from the frequency distributions in Figure 1.

Figure 4. The overall biochemical risk of forming calcium-containing stones (PSF) in three groups of normal subjects and in various groups of primary and secondary calcium stone-formers. SSF = single episode stone-formers; RSF = recurrent idiopathic stone-formers; Hyperparathyroid = patients with primary hyperparathyroidism and stones; dRTA = patients with distal renal tubular acidosis and stones; Enteric = patients with enteric hyperoxaluria and stones; Hereditary = patients with primary hyperoxaluria and stones.

Figure 5. The overall biochemical risk of forming uric acid-containing stones in normal subjects and in patients with idiopathic uric acid stones and in patients with an ileostomy and uric acid stones.

Figure 6. The severity of calcium stone-formation (as defined by the number of stone episodes per year) in a group of recurrent idiopathic calcium stones formers in relation to their biochemical risk of forming stones (P_SF).