Table 3.

Results and risk of bias by outcome for quasiexperimental studies

Study InterventionNo. of ParticipantsOutcomesDirection of EffectP ValueSelection of ParticipantsComparability of GroupsExposureAssessment of OutcomeFollow-UpSummary Risk of Bias
ExperimentalControlExperimentalControl
No. or rate of living donors
 Boulware et al. (24): remove disincentives27 States2.39a1.68a+>0.05Unclear
 Venkataramani et al. (25): remove disincentives16 States2.64b2.47b+0.65X
 Chatterjee et al. (26): education42 Statesc5%dNR+0.07X?
 Chatterjee et al. (26): leave, public employer42 Statesc8%dNR+0.06X?
 Chatterjee et al. (26): leave, private employer42 Statesc8%dNR+0.91X?
 Chatterjee et al. (26): tax benefit42 Statesc4%dNR+0.17X?
 Moore et al. (27): web-based screening12007654+NR
 Schweitzer et al. (22): educationNRNRNRNR+0.02?
No. of living donor evaluations
 Moore et al. (27): web-based screening1200249186+NRLow
 Schweitzer et al. (22): educationNRNR39.4%33.4%+0.03?
No. of contacts with transplant center from potential living donors
 Moore et al. (27): web-based screening1200116e61e+<0.001Low
Stated intent to engage in living donation
 Alvaro et al. (23): campaign405419NRNR=NR????Unclear
  • ✓, low risk of bias; X, high risk of bias; NR, not reported; ?, unclear; +, =, means that there is no difference in the direction of effect between the two groups.

  • a Annual increase in donations per 100,000.

  • b Number of living donations per 100,000.

  • c Includes the District of Columbia.

  • d Change in living donors per capita.

  • e Number of contacts per month.