Table 2

Model coefficients from the segmented regression and estimates of relative change following the interruption for each case study and demographic criteria

TermCoefficient95% CIP valuesR2
Case study A
 Low SESConstant1.619%
Pretrend0.15(−1.48 to 1.80)0.804
Interruption−1.13(−10.0 to 7.75)0.766
Post-trend0.46(−3.56 to 4.48)0.766
Relative change0.57(−4.41 to 5.55)
 Non-selectiveConstant64.470%
Pretrend−1.25(−4.26 to 1.76)0.313
Interruption−12.5(−28.8 to 3.80)0.1
Post-trend6.41(−0.97 to 13.8)0.073
Relative change0.48(−0.02 to 0.97)
 Non-whiteConstant9.6570%
Pretrend1.88(−0.16 to 3.94)0.063
Interruption1.9(−9.20 to 13.0)0.66
Post-trend−4.17(−9.19 to 8.85)0.083
Relative change−0.93(−9.49 to 7.62)
 MaleConstant35.672%
Pretrend1.64(−0.17 to 3.44)0.066
Interruption2.24(−7.54 to 12.0)0.56
Post-trend−3.05(−7.47 to 1.37)0.128
Relative change−0.33(−0.73 to 0.07)
Case study B
 Low SESConstant−0.8342%
Pretrend2.66(−2.82 to 8.17)0.248
Interruption0.82(−9.99 to 11.6)0.844
Post-trend−3.41(−9.42 to 2.62)0.191
Relative change−0.62(−1.27 to 0.03)
 Non-selectiveConstant43.277%
Pretrend0.02(−5.44 to 5.47)0.993
Interruption10.4(−0.35 to 21.1)0.055
Post-trend−3.18(−9.15 to 2.80)0.214
Relative change−0.05(−0.48 to 0.37)
 Non-whiteConstant72.173%
Pretrend−5.16(−15.6 to 5.33)0.244
Interruption−13.4(−34.1 to 7.20)0.145
Post-trend9.62(−1.87 to 21.1)0.081
Relative change0.81(−1.58 to 3.21)
 MaleConstant51.446%
Pretrend−1.78(−5.93 to 2.35)0.298
Interruption3.1(−5.04 to 11.2)0.35
Post-trend2.05(−2.49 to 6.58)0.278
Relative change0.3(−0.23 to 0.85)
Case study C
 Low SESConstant5.3730%
Pretrend−0.51(−2.25 to 1.23)0.463
Interruption0.13(−17.0 to 17.3)0.984
Post-trend2.54(−7.92 to 13.0)0.538
Relative change11.8Non-est*
 Non-selectiveConstant66.758%
Pretrend−1.72(−4.49 to 1.04)0.159
Interruption0.66(−26.6 to 27.9)0.95
Post-trend0.52(−16.1 to 17.1)0.935
Relative change0.07(−0.91 to 1.05)
 Non-whiteConstant30.89%
Pretrend−0.84(−4.81 to 3.13)0.589
Interruption4.65(−34.4 to 43.6)0.757
Post-trend−0.19(−24.0 to 23.6)0.983
Relative change0.14(−2.78 to 3.07)
 MaleConstant44.822%
Pretrend−0.24(−5.09 to 4.60)0.895
Interruption14(−33.6 to 61.7)0.46
Post-trend−4.98(−34.5 to 24.1)0.66
Relative change−0.37(−3.82 to 3.09)
Case study D
 Low SESConstant3.85(−1.43 to 1.78)41%
Pretrend0.19(−1.40 to 1.78)0.758
Interruption−2.5(−11.1 to 6.12)0.466
Post-trend1.5(−2.40 to 5.40)0.346
Relative change1.21Non-est*
 Non-selectiveConstant62.8(41.7 to 83.9)26%
Pretrend−1.55(−7.92 to 4.81)0.535
Interruption2.4(−32.1 to 36.7)0.856
Post-trend−0.48(−16.1 to 15.1)0.936
Relative change−0.01(−1.10 to 1.08)
 Non-whiteConstant31.1(22.0 to 40.1)87%
Pretrend−0.36(−3.08 to 2.37)0.736
Interruption−5.36(−20.1 to 9.41)0.371
Post-trend7.75(1.07 to 14.4)0.032
Relative change1.46(0.37 to 2.54)
 MaleConstant38.3(−21.6 to 54.9)11%
Pretrend0.16(−4.87 to 5.19)0.936
Interruption2.44(−24.8 to 29.7)0.816
Post-trend−0.05(−12.4 to 12.3)0.991
Relative change0.05(−1.03 to 1.14)
  • *Non-est, not estimable due to unrealistic variance because of small sample size.