Table 1.

Interpretation of coefficients from a generalized estimating equation model assessing associations of APOL1 genotype with eGFR measured repeated over time

VariableaCoefficient InterpretationCoefficient EstimateCoefficient SEMP Value
APOL1 high riskDifference in average baseline eGFR (milliliters per minute per 1.73 m2) among African ancestry participants with APOL1 high-risk alleles compare with whites−3.361.130.003
APOL1 low riskDifference in average baseline eGFR (milliliters per minute per 1.73 m2) among African ancestry participants with APOL1 low-risk alleles compare with whites−3.870.63<0.001
YearsAverage eGFR slope (milliliters per minute per 1.73 m2 per year) among whites−0.500.06<0.001
Years × APOL1 high riskDifference in average eGFR slope (milliliters per minute per 1.73 m2 per year) among African ancestry participants with APOL1 high-risk alleles and whites−0.940.21<0.001
Years × APOL1 low riskDifference in average eGFR slope (milliliters per minute per 1.73 m2 per year) among African ancestry participants with APOL1 low-risk alleles and whites−0.380.11<0.001
  • Results are from a generalized estimating equation model fit for the Chronic Renal Insufficiency Cohort Study example in model 1 under exchangeable correlation structure.

  • a Model 1: Embedded Image APOL1 is the exposure variable of the genotype in conjunction with race with three categories (0, white; 1, APOL1 low risk; and 2, APOL1 high risk), with whites as the reference group. The reported coefficient SEMs are the robust estimates combining empirical data correlation and the assumed working correlation structure.