Table 2. Associations between age and discussions about kidney transplantation with medical professionals or social group members.

	Unadjusted	Full modela	Parsimonious modelb
Medical Professionalsc
RR per 5 yrs of age (95% CI)d
Ages 18 to <65 yrs	1.12 (1.03-1.22)	1.13 (1.03-1.24)	1.11 (1.02-1.21)
Ages ≥65 yrs	1.25 (1.15-1.37)	1.28 (1.14-1.42)	1.30 (1.18-1.43)
RR for females compared to males	1.34 (1.02-1.77)	1.45 (1.12-1.89)	1.36 (1.05-1.76)
	Unadjusted	Full modela	Parsimonious modelb
Social Group Memberse
RR per 5 yrs of age (95% CI)f
All ages among all participants	1.08 (1.04-1.13)	1.09 (1.05-1.14)	1.09 (1.04-1.14)
All ages among males	1.06 (0.84-1.34)	1.04 (0.99-1.10)	1.04 (0.98-1.10)
All ages among females	1.16 (1.09-1.23)	1.17 (1.10-1.24)	1.16 (1.09-1.23)

Abbreviations: RR = Relative Risk, CI = Confidence Interval

^aAdjusted for age, sex, race, number of comorbidities, body mass index, ever smoking, household size, time on dialysis, and time between first seeing a nephrologist and dialysis initiation.

^bParsimonious model derived using AIC from the Full model.

Lack of discussion with medical professional adjusted for sex and ever smoking.

Lack of discussion with social group member outcome adjusted for ever smoking.

^cMedical Professionals include any or all of the following: nephrologist, primary medical doctor, dialysis staff.

^dRelative Risks and 95% CI's were modeled using modified Poisson Regression. Age was modeled as a continuous variable using a linear spline term with a knot at age 65, and the risk was modeled per 5-year increase in age.

^eSocial Group Members include any or all of the following: significant other, family member, friend.

^fRelative Risks and 95% CI's were estimated using modified Poisson regression. Age was modeled as a continuous variable per 5-year increase in age.

The relative risk for discussion about kidney transplantation (KT) with medical professionals in the full model is interpreted as: for each 5-year increase in age, after adjusting for sex, race, number of comorbidities, body mass index, ever smoking, household size, time on dialysis, and time between first seeing a nephrologist and dialysis initiation, those aged <65 years were 1.13 fold less likely (95% CI: 1.03-1.24) and those aged ≥65 years were 1.28-fold less likely (95% CI: 1.14-1.42) to have had a discussion about KT. In other words, for example, a person aged 75 years was 2.09-fold less likely to have had a discussion about KT with a medical professional compared to a person aged 55 years (RR = 2.09 = 1.13² * 1.28²). The relative risk for discussion about KT with social group members in the full model is interpreted as: for each 5-year increase in age, after adjusting for race, number of comorbidities, body mass index, ever smoking, household size, time on dialysis, and time between first seeing a nephrologist and dialysis initiation, females were 1.17-fold less likely (95% CI: 1.10-1.24) and males were 1.04-fold less likely (95% CI: 0.99-1.10) to have had a discussion about KT with a social group member.