true

Engagement in Stage 1

The table below presents the demographics of students randomized to an API, divied up by whether they “participated” in the first stage. We define “participation” as completing at least one self-monitoring survey and viewing at least one PNF page.

NOTE: Some students clicked on the link but did not view any PNF pages. An alternate definition of participation could include these students.

No Stage 1 participation
(N=174)		 Stage 1 participation
(N=376)		 Overall
(N=550)
Sex
Male 65 (37.4%) 135 (35.9%) 200 (36.4%)
Female 109 (62.6%) 241 (64.1%) 350 (63.6%)
Race/ethnicity
Asian 19 (10.9%) 40 (10.6%) 59 (10.7%)
Black 2 (1.1%) 15 (4.0%) 17 (3.1%)
Hispanic/Latinx 9 (5.2%) 18 (4.8%) 27 (4.9%)
White 135 (77.6%) 282 (75.0%) 417 (75.8%)
Other/Multi 9 (5.2%) 21 (5.6%) 30 (5.5%)
Pre-college drinking
Never 40 (23.0%) 109 (29.0%) 149 (27.1%)
1 to 9 occasions 63 (36.2%) 146 (38.8%) 209 (38.0%)
10+ occasions 71 (40.8%) 121 (32.2%) 192 (34.9%)
Pre-college binge drinking (times/30 days)
None 107 (61.5%) 291 (77.4%) 398 (72.4%)
1 time 35 (20.1%) 38 (10.1%) 73 (13.3%)
2 times 18 (10.3%) 25 (6.6%) 43 (7.8%)
3-5 times 10 (5.7%) 16 (4.3%) 26 (4.7%)
6-9 times 4 (2.3%) 5 (1.3%) 9 (1.6%)
10+ times 0 (0%) 1 (0.3%) 1 (0.2%)
Pre-college intention to pledge Greek life
No 95 (54.6%) 251 (66.8%) 346 (62.9%)
Yes 25 (14.4%) 38 (10.1%) 63 (11.5%)
Undecided 54 (31.0%) 87 (23.1%) 141 (25.6%)
Residence
Campus housing 164 (94.3%) 344 (91.5%) 508 (92.4%)
Other 10 (5.7%) 32 (8.5%) 42 (7.6%)
Parents' highest level of education
Bachelor's or higher 135 (77.6%) 304 (80.9%) 439 (79.8%)
Less than bachelor's 38 (21.8%) 65 (17.3%) 103 (18.7%)
Don't know 1 (0.6%) 7 (1.9%) 8 (1.5%)
Biological family member with clear drinking problem
No 108 (62.1%) 236 (62.8%) 344 (62.5%)
Yes 66 (37.9%) 139 (37.0%) 205 (37.3%)
Missing 0 (0%) 1 (0.3%) 1 (0.2%)
Pre-college influence of religious beliefs (0(none) to 4(extreme))
Mean (SD) 2.11 (1.27) 2.15 (1.28) 2.14 (1.28)
Missing 3 (1.7%) 2 (0.5%) 5 (0.9%)
Group
Experimental Early 94 (54.0%) 183 (48.7%) 277 (50.4%)
Experimental Late 80 (46.0%) 193 (51.3%) 273 (49.6%)

Factors associated with participating in Stage 1

## 
## Call:
## glm(formula = partS1 ~ age + sex + white + precolDrink + precolBinge + 
##     greek + living_on_campus + parent_college + bio_drinking_prob + 
##     DGreligion_infl_curr + Group, family = "binomial", data = API.compdat)
## 
## Deviance Residuals: 
##     Min       1Q   Median       3Q      Max  
## -1.8444  -1.2753   0.7327   0.8564   1.3953  
## 
## Coefficients:
##                                    Estimate Std. Error z value Pr(>|z|)   
## (Intercept)                         0.98984    0.35227   2.810  0.00496 **
## age                                -0.26547    0.37499  -0.708  0.47898   
## sexFemale                           0.09420    0.20447   0.461  0.64501   
## whiteWhite                         -0.09300    0.24371  -0.382  0.70276   
## precolDrink1 to 9 occasions         0.02577    0.25811   0.100  0.92047   
## precolDrink10+ occasions            0.09241    0.30526   0.303  0.76210   
## precolBinge1-2 times               -0.79350    0.26117  -3.038  0.00238 **
## precolBinge>2 times                -0.48958    0.41849  -1.170  0.24205   
## greekYes                           -0.46400    0.30113  -1.541  0.12335   
## greekUndecided                     -0.38542    0.22235  -1.733  0.08302 . 
## living_on_campusOther               0.51016    0.41239   1.237  0.21606   
## parent_collegeLess than bachelor's -0.37734    0.24553  -1.537  0.12433   
## bio_drinking_probYes                0.08929    0.20054   0.445  0.65614   
## DGreligion_infl_curr                0.02271    0.07589   0.299  0.76480   
## GroupExperimental Late              0.24269    0.19308   1.257  0.20877   
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for binomial family taken to be 1)
## 
##     Null deviance: 677.31  on 543  degrees of freedom
## Residual deviance: 651.81  on 529  degrees of freedom
## AIC: 681.81
## 
## Number of Fisher Scoring iterations: 4

Predictors of completing at least one self-monitoring survey

## 
## Call:
## glm(formula = any_sm ~ sex + precolDrink + precolBinge + greek + 
##     living_on_campus + parent_college + bio_drinking_prob + DGreligion_infl_curr + 
##     Group, family = "binomial", data = API.compdat)
## 
## Deviance Residuals: 
##     Min       1Q   Median       3Q      Max  
## -2.8283   0.2366   0.2796   0.3940   0.7694  
## 
## Coefficients:
##                                      Estimate Std. Error z value Pr(>|z|)    
## (Intercept)                         3.316e+00  6.453e-01   5.139 2.76e-07 ***
## sexFemale                          -7.240e-05  4.118e-01   0.000   0.9999    
## precolDrink1 to 9 occasions         2.374e-02  5.959e-01   0.040   0.9682    
## precolDrink10+ occasions            1.046e-01  6.622e-01   0.158   0.8745    
## precolBinge1-2 times               -1.009e+00  4.785e-01  -2.108   0.0351 *  
## precolBinge>2 times                -6.360e-01  7.564e-01  -0.841   0.4005    
## greekYes                           -1.102e+00  4.983e-01  -2.211   0.0270 *  
## greekUndecided                     -6.494e-01  4.380e-01  -1.483   0.1382    
## living_on_campusOther               1.551e+01  9.755e+02   0.016   0.9873    
## parent_collegeLess than bachelor's  5.144e-01  5.648e-01   0.911   0.3624    
## bio_drinking_probYes               -3.465e-01  3.794e-01  -0.913   0.3610    
## DGreligion_infl_curr                5.092e-02  1.530e-01   0.333   0.7393    
## GroupExperimental Late              7.587e-02  3.805e-01   0.199   0.8419    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for binomial family taken to be 1)
## 
##     Null deviance: 243.41  on 543  degrees of freedom
## Residual deviance: 222.50  on 531  degrees of freedom
## AIC: 248.5
## 
## Number of Fisher Scoring iterations: 17
## 
## Call:
## glm(formula = any_sm ~ precolBinge + greek + living_on_campus, 
##     family = "binomial", data = API.compdat)
## 
## Deviance Residuals: 
##     Min       1Q   Median       3Q      Max  
## -2.6269   0.2540   0.2540   0.4164   0.6796  
## 
## Coefficients:
##                       Estimate Std. Error z value Pr(>|z|)    
## (Intercept)             3.4182     0.3213  10.638   <2e-16 ***
## precolBinge1-2 times   -1.0163     0.3993  -2.545   0.0109 *  
## precolBinge>2 times    -0.5798     0.6686  -0.867   0.3859    
## greekYes               -1.0538     0.4881  -2.159   0.0309 *  
## greekUndecided         -0.5937     0.4316  -1.376   0.1689    
## living_on_campusOther  15.5921   995.0054   0.016   0.9875    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for binomial family taken to be 1)
## 
##     Null deviance: 243.41  on 543  degrees of freedom
## Residual deviance: 224.24  on 538  degrees of freedom
## AIC: 236.24
## 
## Number of Fisher Scoring iterations: 17

Stepwise procedure selected pre-college binge drinking and intention to pledge greek life as predictors.

Predictors of partially completing the PNF

We considered three levels of PNF completion: none, partial or full.

##                                    Value Std. Error t value p value
## age                                0.822      0.374  -0.526   0.599
## sexFemale                          1.172      0.204   0.779   0.436
## whiteWhite                         0.816      0.248  -0.820   0.412
## precolDrink1 to 9 occasions        0.952      0.258  -0.191   0.849
## precolDrink10+ occasions           1.056      0.307   0.177   0.860
## precolBinge1-2 times               0.567      0.263  -2.152   0.031
## precolBinge>2 times                0.696      0.430  -0.844   0.399
## greekYes                           0.807      0.310  -0.693   0.488
## greekUndecided                     0.713      0.223  -1.518   0.129
## living_on_campusOther              0.916      0.361  -0.244   0.807
## parent_collegeLess than bachelor's 0.587      0.242  -2.200   0.028
## bio_drinking_probYes               1.233      0.204   1.026   0.305
## DGreligion_infl_curr               0.973      0.076  -0.364   0.716
## GroupExperimental Late             1.229      0.194   1.065   0.287
## 0|1                                0.246      0.360  -3.891   0.000
## 1|2                                0.292      0.359  -3.428   0.001
##                                    Value Std. Error t value p value
## precolBinge1-2 times               0.552      0.222  -2.683   0.007
## precolBinge>2 times                0.759      0.381  -0.722   0.470
## parent_collegeLess than bachelor's 0.625      0.226  -2.075   0.038
## 0|1                                0.269      0.132  -9.928   0.000
## 1|2                                0.319      0.129  -8.872   0.000

The stepwise procedure selects parent’s education status (college educated vs not) and pre-college binge frequency as the main predictors. Both pre-college drinking and having a parent who is not college educated (vs. is) reduced the odds of some engagement (vs. none).

Engagement in Stage 2

Partial or full completion

Partial or full completion is completing more than 0% of the pages (WebBasics) or exhanging at least one message to the health coach.

0
(N=100)		 1
(N=58)		 Overall
(N=158)
Sex
Male 41 (41.0%) 17 (29.3%) 58 (36.7%)
Female 59 (59.0%) 41 (70.7%) 100 (63.3%)
Race/ethnicity
Asian 6 (6.0%) 3 (5.2%) 9 (5.7%)
Black 0 (0%) 0 (0%) 0 (0%)
Hispanic/Latinx 4 (4.0%) 1 (1.7%) 5 (3.2%)
White 87 (87.0%) 50 (86.2%) 137 (86.7%)
Other/Multi 3 (3.0%) 4 (6.9%) 7 (4.4%)
Pre-college drinking
Never 4 (4.0%) 2 (3.4%) 6 (3.8%)
1 to 9 occasions 23 (23.0%) 21 (36.2%) 44 (27.8%)
10+ occasions 73 (73.0%) 35 (60.3%) 108 (68.4%)
Pre-college binge drinking (times/30 days)
None 39 (39.0%) 23 (39.7%) 62 (39.2%)
1 time 22 (22.0%) 17 (29.3%) 39 (24.7%)
2 times 19 (19.0%) 11 (19.0%) 30 (19.0%)
3-5 times 15 (15.0%) 6 (10.3%) 21 (13.3%)
6-9 times 4 (4.0%) 1 (1.7%) 5 (3.2%)
10+ times 1 (1.0%) 0 (0%) 1 (0.6%)
Pre-college intention to pledge Greek life
No 45 (45.0%) 34 (58.6%) 79 (50.0%)
Yes 22 (22.0%) 8 (13.8%) 30 (19.0%)
Undecided 33 (33.0%) 16 (27.6%) 49 (31.0%)
Residence
Campus housing 99 (99.0%) 58 (100%) 157 (99.4%)
Other 1 (1.0%) 0 (0%) 1 (0.6%)
Parents' highest level of education
Bachelor's or higher 80 (80.0%) 45 (77.6%) 125 (79.1%)
Less than bachelor's 20 (20.0%) 12 (20.7%) 32 (20.3%)
Don't know 0 (0%) 1 (1.7%) 1 (0.6%)
Biological family member with clear drinking problem
No 57 (57.0%) 30 (51.7%) 87 (55.1%)
Yes 43 (43.0%) 28 (48.3%) 71 (44.9%)
Pre-college influence of religious beliefs (0(none) to 4(extreme))
Mean (SD) 2.10 (1.23) 2.14 (1.26) 2.11 (1.24)
Missing 1 (1.0%) 0 (0%) 1 (0.6%)
Group
Experimental Early 45 (45.0%) 30 (51.7%) 75 (47.5%)
Experimental Late 55 (55.0%) 28 (48.3%) 83 (52.5%)
Stage.2.Intervention
Basics 46 (46.0%) 32 (55.2%) 78 (49.4%)
Coach 54 (54.0%) 26 (44.8%) 80 (50.6%) 

## 
## Call:
## glm(formula = participated_cor ~ precolDrink, family = "binomial", 
##     data = dat.HD[-c(47), ])
## 
## Deviance Residuals: 
##     Min       1Q   Median       3Q      Max  
## -1.1101  -0.8901  -0.8901   1.2462   1.4950  
## 
## Coefficients:
##                          Estimate Std. Error z value Pr(>|z|)
## (Intercept)               -0.1603     0.2838  -0.565    0.572
## precolDrink10+ occasions  -0.5610     0.3507  -1.600    0.110
## 
## (Dispersion parameter for binomial family taken to be 1)
## 
##     Null deviance: 206.82  on 156  degrees of freedom
## Residual deviance: 204.27  on 155  degrees of freedom
## AIC: 208.27
## 
## Number of Fisher Scoring iterations: 4

A stepwise procedure chooses pre-college drinking (10+ occastions vs < 10 occasions) as the main predictor, although there were no significant predictors.

Level of engagement (none, just visited, partial, complete)

Some students did not complete the stage 2 intervention but did “visit” the website or the health coach. Therefore, we considered four levels of engagement: none, “just visited”, partial and complete. Just visited for WebBasics is clicking on the link but not completing any pages and just visited for the health coach is visiting the coach but not exchanging any messages.

table1(~ age + sex + race + ALCfreq_life + ALCfreqbinge_30days_lab + greek +
         living_on_campus + parent_highest_ed + bio_drinking_prob + DGreligion_infl_curr + Group
       +Stage.2.Intervention |engagement, data=dat.HD,
       render.continuous=c(.="Mean (SD)"))
None
(N=57)		 Just visited
(N=43)		 Partial
(N=26)		 Complete
(N=32)		 Overall
(N=158)
Age (years)
Mean (SD) 18.1 (0.225) 18.0 (0.213) 18.0 (0.196) 18.0 (0) 18.0 (0.192)
Sex
Male 26 (45.6%) 15 (34.9%) 12 (46.2%) 5 (15.6%) 58 (36.7%)
Female 31 (54.4%) 28 (65.1%) 14 (53.8%) 27 (84.4%) 100 (63.3%)
Race/ethnicity
Asian 2 (3.5%) 4 (9.3%) 1 (3.8%) 2 (6.3%) 9 (5.7%)
Black 0 (0%) 0 (0%) 0 (0%) 0 (0%) 0 (0%)
Hispanic/Latinx 3 (5.3%) 1 (2.3%) 0 (0%) 1 (3.1%) 5 (3.2%)
White 49 (86.0%) 38 (88.4%) 24 (92.3%) 26 (81.3%) 137 (86.7%)
Other/Multi 3 (5.3%) 0 (0%) 1 (3.8%) 3 (9.4%) 7 (4.4%)
Pre-college drinking
Never 3 (5.3%) 1 (2.3%) 1 (3.8%) 1 (3.1%) 6 (3.8%)
1 to 9 occasions 10 (17.5%) 13 (30.2%) 10 (38.5%) 11 (34.4%) 44 (27.8%)
10+ occasions 44 (77.2%) 29 (67.4%) 15 (57.7%) 20 (62.5%) 108 (68.4%)
Pre-college binge drinking (times/30 days)
None 19 (33.3%) 20 (46.5%) 10 (38.5%) 13 (40.6%) 62 (39.2%)
1 time 14 (24.6%) 8 (18.6%) 9 (34.6%) 8 (25.0%) 39 (24.7%)
2 times 12 (21.1%) 7 (16.3%) 5 (19.2%) 6 (18.8%) 30 (19.0%)
3-5 times 9 (15.8%) 6 (14.0%) 1 (3.8%) 5 (15.6%) 21 (13.3%)
6-9 times 2 (3.5%) 2 (4.7%) 1 (3.8%) 0 (0%) 5 (3.2%)
10+ times 1 (1.8%) 0 (0%) 0 (0%) 0 (0%) 1 (0.6%)
Pre-college intention to pledge Greek life
No 25 (43.9%) 20 (46.5%) 14 (53.8%) 20 (62.5%) 79 (50.0%)
Yes 11 (19.3%) 11 (25.6%) 3 (11.5%) 5 (15.6%) 30 (19.0%)
Undecided 21 (36.8%) 12 (27.9%) 9 (34.6%) 7 (21.9%) 49 (31.0%)
Residence
Campus housing 57 (100%) 42 (97.7%) 26 (100%) 32 (100%) 157 (99.4%)
Other 0 (0%) 1 (2.3%) 0 (0%) 0 (0%) 1 (0.6%)
Parents' highest level of education
Bachelor's or higher 48 (84.2%) 32 (74.4%) 21 (80.8%) 24 (75.0%) 125 (79.1%)
Less than bachelor's 9 (15.8%) 11 (25.6%) 5 (19.2%) 7 (21.9%) 32 (20.3%)
Don't know 0 (0%) 0 (0%) 0 (0%) 1 (3.1%) 1 (0.6%)
Biological family member with clear drinking problem
No 34 (59.6%) 23 (53.5%) 13 (50.0%) 17 (53.1%) 87 (55.1%)
Yes 23 (40.4%) 20 (46.5%) 13 (50.0%) 15 (46.9%) 71 (44.9%)
Pre-college influence of religious beliefs (0(none) to 4(extreme))
Mean (SD) 2.20 (1.24) 1.98 (1.22) 2.12 (1.28) 2.16 (1.27) 2.11 (1.24)
Missing 1 (1.8%) 0 (0%) 0 (0%) 0 (0%) 1 (0.6%)
Group
Experimental Early 24 (42.1%) 21 (48.8%) 12 (46.2%) 18 (56.3%) 75 (47.5%)
Experimental Late 33 (57.9%) 22 (51.2%) 14 (53.8%) 14 (43.8%) 83 (52.5%)
Stage.2.Intervention
Basics 30 (52.6%) 16 (37.2%) 12 (46.2%) 20 (62.5%) 78 (49.4%)
Coach 27 (47.4%) 27 (62.8%) 14 (53.8%) 12 (37.5%) 80 (50.6%) 
## Call:
## polr(formula = englevel ~ age + sex + white + precolDrink + precolBinge + 
##     greek + living_on_campus + parent_college + bio_drinking_prob + 
##     DGreligion_infl_curr + Group, data = dat.HD[-c(47), ], Hess = TRUE)
## 
## Coefficients:
##                                       Value Std. Error  t value
## age                                -0.74700     0.8121 -0.91980
## sexFemale                           0.62778     0.3242  1.93654
## whiteWhite                          0.11436     0.4612  0.24797
## precolDrink10+ occasions           -0.48278     0.3481 -1.38707
## precolBinge1-2 times               -0.01607     0.3364 -0.04776
## precolBinge>2 times                -0.13528     0.4872 -0.27767
## greekYes                           -0.41076     0.4068 -1.00967
## greekUndecided                     -0.42395     0.3572 -1.18687
## living_on_campusOther              -1.48885     1.5853 -0.93915
## parent_collegeLess than bachelor's  0.39852     0.3914  1.01832
## bio_drinking_probYes                0.24924     0.3026  0.82376
## DGreligion_infl_curr                0.02299     0.1247  0.18436
## GroupExperimental Late             -0.37240     0.3129 -1.19003
## 
## Intercepts:
##     Value    Std. Error t value 
## 0|1 -14.1428  14.6895    -0.9628
## 1|2 -12.9474  14.6816    -0.8819
## 2|3 -12.0715  14.6772    -0.8225
## 
## Residual Deviance: 408.2949 
## AIC: 440.2949
##                                    Value Std. Error t value p value
## age                                0.474      0.812  -0.920   0.358
## sexFemale                          1.873      0.324   1.937   0.053
## whiteWhite                         1.121      0.461   0.248   0.804
## precolDrink10+ occasions           0.617      0.348  -1.387   0.165
## precolBinge1-2 times               0.984      0.336  -0.048   0.962
## precolBinge>2 times                0.873      0.487  -0.278   0.781
## greekYes                           0.663      0.407  -1.010   0.313
## greekUndecided                     0.654      0.357  -1.187   0.235
## living_on_campusOther              0.226      1.585  -0.939   0.348
## parent_collegeLess than bachelor's 1.490      0.391   1.018   0.309
## bio_drinking_probYes               1.283      0.303   0.824   0.410
## DGreligion_infl_curr               1.023      0.125   0.184   0.854
## GroupExperimental Late             0.689      0.313  -1.190   0.234
## 0|1                                0.000     14.690  -0.963   0.336
## 1|2                                0.000     14.682  -0.882   0.378
## 2|3                                0.000     14.677  -0.822   0.411
##                          Value Std. Error t value p value
## sexFemale                1.900      0.302   2.125   0.034
## precolDrink10+ occasions 0.595      0.310  -1.676   0.094
## 0|1                      0.580      0.335  -1.627   0.104
## 1|2                      1.840      0.332   1.838   0.066
## 2|3                      4.308      0.350   4.172   0.000

The exponentiated coefficients are displayed. There were no significant predictors for participation in the Stage 2 intervention, however, being female increases the odds of some level of participation (vs. none) by 87%. A stepwise procedure selects sex and pre-college drinking (10+ occations vs. >10 occations) as the main predictors.

Overall participation in API (both stage 1 and stage 2)

Overall participation is defined as partially completing the PNF (viewing at least one page) AND completing at least one self-monitoring survey. Heavy drinkers must have also either sent at least one message to the coach or had partial completion of web-BASICS, in addition to the previous criteria.

No overall participation
(N=241)		 API participation
(N=309)		 Overall
(N=550)
age
Mean (SD) 0.0705 (0.257) 0.0583 (0.235) 0.0636 (0.244)
Sex
Male 93 (38.6%) 107 (34.6%) 200 (36.4%)
Female 148 (61.4%) 202 (65.4%) 350 (63.6%)
Race/ethnicity
Asian 23 (9.5%) 36 (11.7%) 59 (10.7%)
Black 2 (0.8%) 15 (4.9%) 17 (3.1%)
Hispanic/Latinx 12 (5.0%) 15 (4.9%) 27 (4.9%)
White 193 (80.1%) 224 (72.5%) 417 (75.8%)
Other/Multi 11 (4.6%) 19 (6.1%) 30 (5.5%)
Pre-college drinking
Never 43 (17.8%) 106 (34.3%) 149 (27.1%)
1 to 9 occasions 78 (32.4%) 131 (42.4%) 209 (38.0%)
10+ occasions 120 (49.8%) 72 (23.3%) 192 (34.9%)
Pre-college binge drinking (times/30 days)
None 138 (57.3%) 260 (84.1%) 398 (72.4%)
1 time 47 (19.5%) 26 (8.4%) 73 (13.3%)
2 times 28 (11.6%) 15 (4.9%) 43 (7.8%)
3-5 times 21 (8.7%) 5 (1.6%) 26 (4.7%)
6-9 times 6 (2.5%) 3 (1.0%) 9 (1.6%)
10+ times 1 (0.4%) 0 (0%) 1 (0.2%)
Pre-college intention to pledge Greek life
No 124 (51.5%) 222 (71.8%) 346 (62.9%)
Yes 41 (17.0%) 22 (7.1%) 63 (11.5%)
Undecided 76 (31.5%) 65 (21.0%) 141 (25.6%)
Residence
Campus housing 230 (95.4%) 278 (90.0%) 508 (92.4%)
Other 11 (4.6%) 31 (10.0%) 42 (7.6%)
Parents' highest level of education
Bachelor's or higher 191 (79.3%) 248 (80.3%) 439 (79.8%)
Less than bachelor's 49 (20.3%) 54 (17.5%) 103 (18.7%)
Don't know 1 (0.4%) 7 (2.3%) 8 (1.5%)
Biological family member with clear drinking problem
No 146 (60.6%) 198 (64.1%) 344 (62.5%)
Yes 95 (39.4%) 110 (35.6%) 205 (37.3%)
Missing 0 (0%) 1 (0.3%) 1 (0.2%)
Pre-college influence of religious beliefs (0(none) to 4(extreme))
Mean (SD) 2.09 (1.29) 2.17 (1.27) 2.14 (1.28)
Missing 3 (1.2%) 2 (0.6%) 5 (0.9%)
Group
Experimental Early 122 (50.6%) 155 (50.2%) 277 (50.4%)
Experimental Late 119 (49.4%) 154 (49.8%) 273 (49.6%)

Predictors of participating/engaging in the API

## [1] 336 140 252 330 369 451

The exponentiated coefficients and p-values are presented. A stepwise regression procedure selects pre-college binge drinking, pre-college drinking, whether one lives on campus, pre-college intention to pledge Greek life and sex as predictors. Overall, female students (p = .099) and students who live outside campus (p=.103) had higher odds of participating in the adaptive intervention compared to male students and students living on campus, although these associations were not significant.

However, intention to pledge Greek life, pre-college binge frequency (1-2 times, >2 times vs. No) and pre-college drinking (10+ occasions vs. 1-9 occasions vs. Never) were consistently significant in all the models we explored.

Intending to pledge Greek life or being undecided is associated with a 62% (p=.002) and 39% (p=.024) reduction in the odds of participating in the intervention compared to students who do not intend to pledge greek life. The odds of participating for students who binge drank more than 2 times or 1-2 times/month before college was 72% (p=.005) and 55% (p=.002) less than students who never binge drank, respectively. Additionally, drinking at least 10 times before college reduced the odds of participating in the adaptive intervention by 51% (p=.008).