Table 2.

Percentage annual change in kidney function in relation to 24-hour urine volume at baseline (n = 2145a)

Age and Gender AdjustedFully Adjusted
ChangebPChangebP
Intercept−0.830.08−1.030.03
Age−0.010.010.010.50
Gender (reference: male)0.060.76−0.080.71
Urine volume (reference: 1 to 1.9 L/day)
    <1 L/day−0.220.45−0.200.51
    2 to 2.9 L/day0.110.640.120.62
    ≥3 L/day0.870.020.860.02
Dipstick protein ≥1 g/L−2.56<0.01
Medications for hypertension (including diuretics)−0.630.01
Cardiovascular disease−1.230.01
  • a Excludes three outliers with strong positive skew in estimated GFR decline.

  • b Multiple linear regression: models were reduced using backward elimination at alpha = 0.1518,19 unless elimination changed the association with urine volume by >10%;19,20 age and gender were forced into all models.