Casual Contraception in Casual Sex
Sensitivity of the Findings to Sorority/Fraternity Membership

Supplemental Table G1. Sensitivity of the Findings Trend to Sorority/Fraternity Membership
Models Estimating the Odds of Condom Use
Eq 2 Eq 2 + Greek Eq 3 Eq 3 + Greek
WomenMenWomenMenWomenMenWomenMen
Year of College
Freshman Year
Sophomore Year0.68**0.62*0.67**0.63*
Junior Year0.72**0.63*0.72**0.63*
Senior Year0.63***0.62*0.63***0.62*
During/After Freshman Year
First Year of College
Years 2/3/4 of College0.51**0.36*0.53**0.34**
Mother's Educational Attainment
Mother Received a High School Education or Less
Mother Received Some College Education0.920.900.920.900.900.46^0.900.47^
Mother Received a Bachelor's Degree0.861.030.861.030.730.740.730.73
Mother Received a Graduate Degree0.890.800.910.810.55*0.35*0.56*0.35*
Grade × Mother's Educational Attainment
Years 2/3/4 × Some College1.022.35^1.032.32^
Years 2/3/4 × Bachelor's Degree1.221.511.221.54
Years 2/3/4 × Graduate Degree1.92*2.94*1.93*2.95*
School Gender Composition
≤ 53% Female
≥ 53% Female1.051.211.141.09
≥ 53% Female × Years 2/3/41.130.86
Population Density During High School
Rural0.900.860.900.860.880.870.890.87
Small Town1.120.901.120.901.110.911.120.90
Suburban
Medium City1.23^0.881.22^0.881.23^0.891.22^0.88
Large City1.29^1.371.271.361.29^1.371.261.37
Respondent's Race
White
Black0.962.63*1.002.60*0.982.61*1.022.60*
Hispanic1.321.161.36^1.171.311.201.35^1.22
Asian0.991.190.971.180.991.220.971.21
Other Race1.240.971.250.971.230.921.250.92
Mixed Race1.131.101.131.091.131.081.131.07
Partner's Race
White
Black1.77**0.731.82**0.721.78**0.741.82**0.74
Hispanic0.940.870.930.880.940.840.930.85
Asian0.821.200.811.210.811.190.811.20
Mixed Race0.911.110.901.120.911.140.901.14
Other or Not Indicated0.681.220.681.210.671.230.671.23
Childhood Religion
Catholic0.921.53*0.911.52*0.921.53*0.921.52*
Jewish1.301.431.251.451.341.491.301.51
Other Religion0.841.050.841.050.841.080.851.07
Protestant1.241.331.251.361.241.321.251.34
None
Immigrant1.041.431.041.441.041.411.031.42
student is a member of a fraternity or sorority1.220.901.210.89
Observations25821252257412472582125225741247
Supplemental Table G2. Sensitivity of the Findings Trend to Sorority/Fraternity Membership, When Hooking Up With a Partner From the Same College
Models Estimating the Odds of Condom Use
Eq 2 Eq 2 + Greek Eq 3 Eq 3 + Greek
WomenMenWomenMenWomenMenWomenMen
Year of College
Freshman Year
Sophomore Year0.56***0.60*0.55***0.60^
Junior Year0.69*0.59^0.68*0.60^
Senior Year0.60**0.51*0.60**0.52*
During/After Freshman Year
First Year of College
Years 2/3/4 of College0.26**0.32^0.33**0.28*
Mother's Educational Attainment
Mother Received a High School Education or Less
Mother Received Some College Education0.800.770.800.770.580.29^0.580.29^
Mother Received a Bachelor's Degree0.63*0.830.63*0.830.37*0.780.38*0.74
Mother Received a Graduate Degree0.62*0.650.62*0.650.29**0.22*0.30**0.22*
Grade × Mother's Educational Attainment
Years 2/3/4 × Some College1.453.40^1.473.38^
Years 2/3/4 × Bachelor's Degree1.901.061.901.13
Years 2/3/4 × Graduate Degree2.81*3.85^2.66*3.83^
School Gender Composition
≤ 53% Female
≥ 53% Female0.862.001.26^1.57
≥ 53% Female × Years 2/3/41.68^0.74
Population Density During High School
Rural0.970.660.970.660.930.670.950.67
Small Town1.291.011.291.011.271.021.291.02
Suburban
Medium City1.37^0.731.36^0.731.320.721.320.72
Large City1.70*1.401.69*1.401.69*1.431.67*1.44
Respondent's Race
White
Black0.861.950.871.930.871.980.891.98
Hispanic1.542.27^1.542.26^1.502.51^1.512.52^
Asian0.970.970.960.970.991.000.991.00
Other Race1.420.521.430.521.350.441.380.43
Mixed Race1.231.141.221.141.211.131.201.14
Partner's Race
White
Black1.370.761.380.761.400.891.400.88
Hispanic0.911.210.911.220.861.160.851.15
Asian0.951.220.941.230.981.270.951.28
Mixed Race0.901.150.901.150.871.270.871.26
Other or Not Indicated0.44*1.750.44*1.750.41*1.950.43*1.91
Childhood Religion
Catholic0.841.300.841.310.861.350.881.34
Jewish1.191.031.171.031.241.131.261.12
Other Religion0.841.730.831.740.881.83^0.881.83^
Protestant1.300.911.290.911.310.871.320.88
None
Immigrant1.281.041.281.041.300.991.290.98
student is a member of a fraternity or sorority1.080.971.060.94
Observations1375784137478313757841374783
Supplemental Table G3. Sensitivity of the Findings Trend to Sorority/Fraternity Membership, When Hooking Up With a Partner Who Does Not Attend the Same College
Models Estimating the Odds of Condom Use
Eq 2 Eq 2 + Greek Eq 3 Eq 3 + Greek
WomenMenWomenMenWomenMenWomenMen
Year of College
Freshman Year
Sophomore Year0.860.680.860.71
Junior Year0.820.740.830.74
Senior Year0.73^0.910.73^0.91
During/After Freshman Year
First Year of College
Years 2/3/4 of College0.800.430.690.46
Mother's Educational Attainment
Mother Received a High School Education or Less
Mother Received Some College Education0.940.980.940.950.930.740.930.75
Mother Received a Bachelor's Degree0.981.020.991.040.960.510.980.54
Mother Received a Graduate Degree1.110.741.150.720.630.390.630.38
Grade × Mother's Educational Attainment
Years 2/3/4 × Some College1.041.421.031.35
Years 2/3/4 × Bachelor's Degree1.002.480.992.33
Years 2/3/4 × Graduate Degree2.09^2.332.21^2.32
School Gender Composition
≤ 53% Female
≥ 53% Female1.410.861.100.86
≥ 53% Female × Years 2/3/40.741.08
Population Density During High School
Rural0.741.270.731.260.731.160.721.13
Small Town0.980.620.970.60^0.980.60^0.960.57^
Suburban
Medium City1.071.011.051.021.071.011.061.01
Large City0.961.010.920.940.951.000.900.93
Respondent's Race
White
Black1.134.39^1.254.17^1.113.82^1.243.50
Hispanic1.060.981.121.071.040.991.091.07
Asian0.811.960.802.090.771.930.792.05
Other Race0.973.47*0.973.64*0.973.33*0.953.53*
Mixed Race1.010.921.030.861.010.921.030.86
Partner's Race
White
Black2.18**0.902.24**0.912.23**0.992.31**1.03
Hispanic1.130.651.120.621.160.671.160.66
Asian0.921.220.911.310.951.300.921.42
Mixed Race1.031.030.991.081.051.001.011.07
Other or Not Indicated1.120.661.140.651.180.681.180.66
Childhood Religion
Catholic1.052.09*1.041.96*1.072.02*1.061.90*
Jewish1.344.03**1.264.41**1.393.77*1.334.15**
Other Religion0.910.640.920.590.910.630.920.58
Protestant1.172.20*1.192.34*1.182.18*1.192.35*
None
Immigrant0.982.17^0.972.35^1.002.24^0.972.41^
student is a member of a fraternity or sorority1.250.53*1.210.52*
Observations1199448119244411994481192444