Examining Age and Racial-Ethnic Differences in Willingness to Donate

Live Kidneys in the United States

Tanjala S. Purnell, Neil R. Powe, Misty U. Troll, Nae-Yuh Wang, Carlton Haywood Jr.,

Thomas A. LaVeist, L. Ebony Boulware

Johns Hopkins School of Public Health, Johns Hopkins School of Medicine, Welch Center for Prevention, Epidemiology, and Clinical

Research; Baltimore, Maryland, United States

Introduction: Need for Live Donor Kidney Transplantation (LDKT) in the US ~560,000 US adults

treated for end stage renal disease (ESRD) with higher prevalence among older adults and racial-ethnic minorities

LDKT offers longer life expectancy and higher quality of life than dialysis treatment

Yet, older adults and minorities less likely to receive LDKT and have difficulties identifying a potential live kidney donor

Source: USRDS Annual Data Report, 2011

ESRD Incident Rates, by Age and Race-Ethnicity

Adults Age 65+

African Americans

Objectives/Research Questions

Primary:• Are there racial-ethnic differences in willingness to

donate a live kidney?

Does age modify potential racial-ethnic

differences in willingness to donate a live kidney?

Secondary:• Do racial-ethnic differences in medical mistrust,

religious concerns, and spiritual concerns mediate potential racial-ethnic differences in willingness?

Methods: Study Design and Sampling Frame

Design: National cross-sectional telephone survey • Standardized 20 minute questionnaire administered by

trained interviewers, Aug 2004 - Aug 2005

Sampling Frame: • Persons age 18-75 years living in households with a

telephone in the continental US (stratified by census division)

• Over-sampling to enrich population with African American and Hispanic (all races) respondents

• Telephones selected by random digit dialing*• Within household randomization of participants**

*(epsem approach- equal probability of selection for each number in sampling frame) **Next-Birthday method

Methods: Willingness to Donate (Outcome)

Example. Please rate your willingness to donate a kidney to the following people from 0 to 10 with 0 being “not willing” 10 being “extremely willing” and 5 being “moderately willing” to donate while you are still alive:

a. Your Parent

b. Your Child

0 1 2 3 4 5 6 7 8 9 10

0 1 2 3 4 5 6 7 8 9 10

Methods: Statistical Analysis

• Chi-square to test associations of differences in baseline characteristics by race-ethnicity

• Exploratory factor analysis to test development of a an overall willingness to donate scale

• Multivariable linear regression to assess racial-ethnic differences in willingness (with age interaction terms)

– Adjusted for confounding: gender, education, annual household

income, marital status, employment status, and census region

– Tests of mediation: medical mistrust, religious concerns, and

spiritual concerns about organ donation

Results: Participant Characteristics (N=845)

Characteristic

OverallN=845*

n (%)

WhiteN=550

AfricanAmerican

N=102

Hispanic(all races)

N=130

P-value

Age Category <0.01

18-44 years 404 (48) 216 (39) 56 (55) 97 (75)

45-59 years 290 (34) 210 (38) 34 (33) 31 (24)

60-75 years 150 (18) 124 (22) 12 (12) 2 (1)

Gender <0.01

Female 533 (63) 351 (64) 76 (75) 87 (67)

Marital Status <0.01

Married or Living w/Partner 474 (56) 346 (63) 37 (36) 71 (55)

Household Income <0.01

$40,000 and below 287 (34) 165 (30) 49 (48) 61 (47)

$40,001 - $60,000 146 (17) 105 (19) 17 (17) 19 (15)

Greater than $60,000 308 (36) 243 (44) 25 (24) 26 (20)

*Including 37 Non-Hispanic ‘Other’ Minorities: American Indian or Alaskan Natives, Native Hawaiian or Other Pacific Islanders, Asians, “Two or More Races,” and “Others”

Results: Participant Characteristics (N=845)

CharacteristicOverallN=845*

WhiteN=550

African American

N=102

Hispanic(all races)

N=130

P-value

Education <0.01

Less than college graduate 411 (49) 248 (45) 62 (61) 85 (65)

Comorbidities 0.08

At least one medical condition 348 (41) 246 (45) 48 (47) 37 (28)

Employment 0.03

Full-time or part-time 548 (65) 371 (67) 67 (66) 84 (65)

Student, homemaker, retired 201 (24) 148 (27) 19 (19) 25 (19)

Disabled or unemployed 58 (7) 30 (5) 13 (13) 13 (10)

Census region <0.01

North East 149 (18) 101 (18) 19 (19) 20 (15)North Central 162 (19) 126 (23) 22 (22) 10 (8)South 291 (34) 185 (34) 56 (55) 39 (30)West 217 (26) 138 (25) 5 (5) 61 (47)

*Including 37 Non-Hispanic ‘Other’ Minorities

Results: Age Modifies Racial Differences in Willingness to Donate to Relatives

Multivariable Regression* (no interaction terms)

Factors

b(95% CI)

p-value

Race-Ethnicity

White (n=550) [reference] African American (n=102) -0.48 (-0.94 to -0.02) 0.04 Hispanic (n=130) 0.06 (-0.39 to 0.51) 0.78Age Categories

18-44 years (n=404) [reference] 45-59 years (n=290) -0.39 (-0.72 to -0.06) 0.02

60-75 years (n=150) -0.61 (-1.09 to -0.13) 0.01

*Linear regression models adjusted for gender, education, household income, marital status, employment, presence of comorbid medical conditions, and US census region.

Interaction Terms

AA and 45-59 years ---- ---- -1.24 (-2.20 to -0.28) 0.01

AA and 60-75 years ---- ---- -1.46 (-2.92 to 0.01) 0.05 Hispanic and 45-59 years ---- ---- -0.61 (-1.57 to 0.35) 0.21 Hispanic and 60-75 years ---- ---- 0.74 (-3.16 to 4.65) 0.71

Multivariable Regression* (with interaction terms)

b(95% CI)

p-value

[reference]0.12 (-0.50 to 0.73) 0.710.29 (-0.24 to 0.81) 0.28

[reference]-0.09 (-0.48 to 0.29) 0.63

-0.34 (-0.86 to 0.16) 0.18

Racial-Ethnic Differences in Willingness to Donate to Relatives: Tests of Mediation by Medical Mistrust and Concerns among Participants Age 45-75 Years (N=440)

White (n=334)

African American

(n=46)

Hispanic (n=33)

Multivariable Linear Regression b p-value b p-value b p-value

A. Model 1* [ref] --- -1.12 0.00 -0.28 0.56

B. Model 1* + Physician Mistrust [ref] --- -1.03 0.01 -0.23 0.62

C. Model 1* + Hospital Mistrust [ref] --- -1.30 0.00 -0.36 0.44

D. Model 1* + Religious Concerns [ref] --- -0.98 0.01 -0.05 0.91

E. Model 1* + Spiritual Concerns [ref] --- -0.55 0.14 -0.26 0.55

G. Model 1* + All Factors [ref] --- -0.59 0.12 -0.06 0.90

*Models adjusted for gender, education, household income, marital status, employment, presence of comorbid medical conditions, and US census region.

Study Limitations and Strengths

Limitations

Cross-sectional ascertainment of attitudes may not reflect behaviors

Only contacted households with telephones, which may not reflect

attitudes of households without telephones

Limited subsample of older racial-ethnic minorities

Strengths

Detailed assessment of factors influencing willingness to donate live

kidneys among a national, diverse group of participants

First study to explore age/race interactions and mediators of

differences in willingness to donate live kidneys

Conclusions and Implications

Racial-ethnic differences in willingness to donate live kidneys to relatives varies by participant age

No racial-ethnic differences in willingness to donate to

non-relatives at any age group

No differences in willingness to donate to relatives or

non-relatives between Hispanics and Whites

Spiritual concerns explained differences in willingness between African Americans and Whites aged 45+ years

Interventions to address spiritual concerns may enhance efforts to improve rates of live kidney donation in the US

Examining Age and Racial-Ethnic Differences in Willingness to Donate

Live Kidneys in the United States

Tanjala S. Purnell, Neil R. Powe, Misty U. Troll, Nae-Yuh Wang, Carlton Haywood Jr.,

Thomas A. LaVeist, L. Ebony Boulware

Johns Hopkins School of Public Health, Johns Hopkins School of Medicine, Welch Center for Prevention, Epidemiology, and Clinical

Research; Baltimore, Maryland, United States

Extra Slides

Presenter Disclosures

Funding Support

• Grant #1 F31 DK084840-01 from the National Institute of Diabetes and Digestive and Kidney Diseases (Purnell)

• Grant #043495 from the Robert Wood Johnson Foundation (Boulware)

Conflicts of Interest• None

Public Health Significance End stage renal disease

(ESRD) associated with poor patient survival and quality of life

~560,000 US adults treated for ESRD and 25 million adults with chronic kidney damage

Disproportionate ESRD burden among older adults and racial-ethnic minorities

African Americans have 2 to 4-fold greater risk of ESRD than Whites Source: USRDS Annual Data Report, 2011

ESRD Incident Rates, by Age and Race-Ethnicity

Adults Age 65+

African Americans

Methods: a. Medical Mistrust, b. Religious Concerns, and c. Spiritual Concerns

a. “I trust [HOSPITALS/PHYSICIANS] to put my medical needs above all other considerations.” (Do you…)

b. “My religious views do not permit organ donation.”

c. “All of my organs must be fully intact in preparation for burial or cremation.” (Do you…)

Completely Agree

Mostly Agree

Somewhat Agree

Agree a Little

Not at All

Strongly Agree

Agree No Opinion

Disagree Don’t Know N/A

Strongly Disagree

Strongly Agree

Agree No Opinion

Disagree Don’t KnowStrongly Disagree

Results: Selection of Study Sample via Random Digit Dialing

Household agreeing to randomization

N =847

Total numbers Attempted (up to 10 attempts)

N=8661

Randomized participantsN =720

(85% of randomized households)

Person in household not reached(AM, BZ, CB, CH, DC, F/C, HO,

HU, NA, NE, NS, OP, ORG, OTH, UL)

N=6828

Refusals before within household randomization

N=986

Refusals after within household randomization

N=77

Household contactedN=1833

AdditionalOver-sampling

58 AA67 Hispanic

N=125

N=845 Total

Completed Interviews

Results: Willingness to Donate Live Kidneys (Scale Development)

Exploratory factor analysis* suggested a 2-factor

solution, which explained 84% of the total variance:

Factor 1: Willingness to donate to Relatives

(parent, child, sibling, spouse)

Factor 2: Willingness to donate to Non-Relatives

(friend, someone famous, stranger)

*We performed principal components analysis and common factor analysis, and examined Pearson’s rank correlation coefficients, eigenvalues, factor loadings, screeplots, and internal consistency.

Results: No Race Differences in Willingness to Donate to Non-Relatives

Multivariable Regression* (no interaction terms)

Factors

b(95% CI)

p-value

Race-Ethnicity

White (n=550) [reference] African American (n=102)

-0.21 (-0.93 to 0.49) 0.55

Hispanic (n=130) 0.39 (-1.08 to 0.29) 0.26Age Categories

18-44 years (n=404) [reference] 45-59 years (n=290) -0.31 (-0.82 to 0.20) 0.23

60-75 years (n=150) -0.86 (-1.60 to -0.11) 0.02

*Linear regression models adjusted for gender, education, household income, marital status, employment, presence of comorbid medical conditions, and US census region.

Multivariable Regression* (with interaction terms)

b(95% CI)

p-value

[reference]0.26 (-0.69 to 1.22) 0.59-0.40 (-1.21 to 0.40) 0.33

[reference]-0.21 (-0.81 to 0.39) 0.49

-0.77 (-1.57 to 0.03) 0.06Interaction Terms

AA and 45-59 years ---- ---- -1.09 (-2.58 to 0.40) 0.15

AA and 60-75 years ---- ---- -0.86 (-3.13 to 1.40) 0.45 Hispanic and 45-59 years ---- ---- 0.08 (-1.41 to 1.56) 0.92 Hispanic and 60-75 years ---- ---- 1.64 (-4.37 to 7.65) 0.59

Results: Racial-Ethnic Differences in Medical Mistrust, Religious and Spiritual Concerns

OverallN=845*

WhiteN=550

African American

N=102

Hispanic(all races)

N=130

P-value

Physician Mistrust <0.01

Less Than Mostly Trust 178 (21) 95 (17) 32 (31) 40 (31)

Hospital Mistrust <0.01

Less Than Mostly Trust 405 (48) 252 (46) 64 (63) 68 (53)

My Religious Views Do Not Permit Donation

<0.01

Agree or Strongly Agree 50 (6) 21 (4) 10 (10) 17 (13)

No Opinion or Don’t Know 163 (19) 88 (16) 30 (29) 37 (28)

All My Organs Must be Intact for Burial/Cremation

<0.01

Agree or Strongly Agree 49 (6) 16 (3) 19 (19) 11 (8)

No Opinion or Don’t Know 43 (5) 15 (3) 8 (8) 18 (14)

*Including 37 Non-Hispanic ‘Other’ Minorities: American Indian or Alaskan Natives, Native Hawaiian or Other Pacific Islanders, Asians, “Two or More Races,” and “Others”

Analysis of Variance Results for Willingness to Donate Live Kidneys

Exploratory Factor Analysis

Exploratory Factor Analysis: Screeplot

Significance of Race-Ethnicity, Age, and Attitudes in Donor Identification (Previous Study Findings)

Differences in Willingness to be a Deceased Donor – Older age, African American race, religiosity/spirituality, and

mistrust in hospitals associated with less willingness to

donate organs after death (Boulware, Transplant, 2002)

– Older age associated with less willingness to donate one’s

own or a relative’s organs after death (Sanner, JAMA, 1994)

Race Differences in Medical Mistrust – African Americans less likely to trust physicians than Whites

(Boulware, Public Health Reports, 2003)

Evidence Suggesting Safety of Live Kidney Donation with Older Donors (Previous Findings)

• Laparoscopic donor nephrectomy may be performed safely in patients older than 60 years of age (Jacobs SC, J Am Coll Surg, 2004)

– No increase in complication rates or length of

hospitalization for donors older than age 60 years

• Our experience confirmed that living donors older than 60 years old provided excellent kidney function at 10 years after transplantation (Berardinelli, Transplant Proc, 2010)

Source: USRDS Annual Data Report, 2011

Disparities in Kidney TransplantationAdjusted Transplant Rates, by Age and Race:

Deceased Kidney Donors Older adults and

minorities significantly less likely to receive kidney transplants

Older patients awaiting a kidney transplant have a higher mortality risk and poorer outcomes than younger patients

Proposed changes to deceased donor organ allocation laws will give greater preference to younger patients