Table 4.

STERGM models for link prediction

VariablesModel 1: Full ModelModel 2: Discussed TransplantModel 3: Requested a Donation
Structural variables, β (SEM), P value
 Edges−8.57 (1.88), <0.001−7.80 (1.79), <0.001−7.99 (1.88), <0.001
 GWDegree (0.25)−0.75 (0.34), 0.03−0.91 (0.33), 0.006−0.90 (0.34), 0.007
 GWESP (0.55)0.80 (0.18), <0.0010.78 (0.18), <0.0010.77 (0.18), <0.001
Dialysis clinic variables, β (SEM), P value
 TTS (sociality)0.37 (0.18), 0.040.41 (0.18), 0.020.33 (0.18), 0.06
 TTS (homophily)3.42 (0.99), <0.0013.42 (0.99), <0.0013.25 (1.02), <0.001
 Average seating distance (per seat; Euclidean)−0.30 (0.10), 0.002−0.28 (0.10), 0.003−0.30 (0.10), 0.003
Patient attributes, β (SEM), P value
 Age
  Yr (sociality)0.01 (0.01), 0.190.01 (0.01), 0.240.01 (0.01), 0.17
  Yr (homophily)−0.01 (0.01), 0.42−0.01 (0.01), 0.31−0.01 (0.01), 0.49
 Sex
  Female sex (sociality)−0.34 (0.32), 0.29−0.29 (0.31), 0.34−0.29 (0.31), 0.34
  Sex (homophily)0.14 (0.27), 0.720.17 (0.38), 0.660.17 (0.40), 0.68
 Race
  White (sociality)REFREFREF
  White (homophily)−0.37 (1.18), 0.75−0.46 (1.18), 0.70−0.40 (1.16), 0.73
  Black (sociality)0.22 (0.49), 0.640.11 (0.48), 0.820.22 (0.48), 0.64
  Black (homophily)0.37 (0.69), 0.600.34 (0.68), 0.620.32 (0.68), 0.64
  Hispanic (sociality)−0.93 (0.46), 0.04−0.96 (0.46), 0.04−0.93 (0.46), 0.04
  Hispanic (homophily)2.31 (0.69), <0.0012.31 (0.66), <0.0012.19 (0.68), 0.001
  Multiethnic (sociality)1.21 (0.53), 0.020.97 (0.52), 0.061.45 (0.52), 0.03
  Multiethnic (homophily)−0.21 (1.33), 0.870.01 (1.38), 0.99−0.43 (1.34), 0.75
Transplant attributes, β (SEM), P value
 Discussed transplant with other patients (sociality)0.23 (0.29), 0.410.41 (0.24), 0.08
 Discussed transplant with other patients (homophily)0.66 (0.35), 0.060.64 (0.31), 0.04
 Requested a donation (sociality)0.49 (0.26), 0.060.49 (0.24), 0.04
 Requested a donation (homophily)−0.23 (0.34), 0.50−0.03 (0.34), 0.93
Model factors
 Null deviance14,187 (df, 10,234)14,187 (df, 10,234)14,187 (df, 10,234)
 Residual deviance474 (df, 10,213)479 (df, 10,215)478 (df, 10,215)
 AIC, BIC517, 669517, 654516, 653
  • This is the STERGM of the variables that are associated with the formation of the hemodialysis-clinic social network. We report the β coefficients, which are the log odds of the formation of link; the SEM of the coefficients; and the P values. Edges represent the log odds of a participant forming a link with another participant, independent of the other variables, and represent the intercept of the model. GWDegree is the log odds of a participant with fewer links (i.e., lower degree) to form a new link compared with those participants with links (i.e., higher degree). GWESPs are the log odds that participants are more likely to link if they already share a link in common with another participant. These effects geometrically diminish as the number of shared links decrease. Sociality represents the propensity of a participant forming a link with any other participant. Homophily represents the propensity of a participant to form a link with another participant with the same attribute. STERGM, separable temporal exponential random graph model; GWDegree, geometrically weighted degree; GWESP, geometrically weighted edgewise shared partner; TTS, Tuesday, Thursday, and Saturday dialysis shift; REF, reference; df, degrees of freedom; AIC, Akaike information criterion; BIC, Bayesian information criterion.