Table 4.

Quintiles of DASH score and the relative risk of incident kidney stones in men (Health Professionals Follow-up Study), older women (Nurses' Health Study I), and younger women (Nurses' Health Study II)a

DASH Score Quintiles
Quintile 1Quintile 2Quintile 3Quintile 4Quintile 5P for Trend
HPFS
    Median DASH score1621242731
    Cases of new stones445416370260226
    Person-years113,406123,848127,562110,087112,924
    Age-adjusted RR1.00.890.790.660.57<0.001
    95% CI(Ref)(0.78 to 1.02)(0.68 to 0.90)(0.56 to 0.77)(0.49 to 0.68)
    Multivariate RRb1.00.890.770.640.55<0.001
    95% CI(Ref)(0.77 to 1.01)(0.67 to 0.89)(0.54 to 0.74)(0.46 to 0.65)
NHS I
    Median DASH score1721242731
    Cases of new stones452372354259238
    Person-years263,851248,556279,617244,572252,017
    Age-adjusted RR1.00.890.760.640.58<0.001
    95% CI(Ref)(0.77 to 1.02)(0.66 to 0.87)(0.55 to 0.74)(0.49 to 0.67)
    Multivariate RRb1.00.890.760.640.58<0.001
    95% CI(Ref)(0.77 to 1.02)(0.65 to 0.87)(0.54 to 0.74)(0.49 to 0.68)
NHS II
    Median DASH score1721242731
    Cases of new stones581547411414300
    Person-years229,342244,892221,988233,327217,330
    Age-adjusted RR1.00.880.730.710.55<0.001
    95% CI(Ref)(0.79 to 0.99)(0.65 to 0.83)(0.62 to 0.80)(0.48 to 0.63)
    Multivariate RRb1.00.920.770.750.60<0.001
    95% CI(Ref)(0.81 to 1.03)(0.68 to 0.88)(0.66 to 0.86)(0.52 to 0.70)
  • aFor illustrative purposes, median DASH scores in HPFS, NHS I, and NHS II are from 1990, 1990, and 1991. However, updated period-specific DASH scores were used in the prospective analyses.

  • bMultivariate model includes age, body mass index, total energy intake, use of thiazide diuretics (yes or no), fluid intake (quintiles), caffeine (quintiles), alcohol use (seven categories), history of hypertension, and history of diabetes.