Long-Term Condition Effects

To examine the long-term effects of the two intervention conditions, a series of MANCOVAs and ANCOVAs were conducted using 6-month follow-up scores as the dependent variables and pre-intervention scores as covariates (section 3.7.2 described these analyses in further detail).

As with the analyses examining the short-term condition effects, the specific assumptions for MANCOVA were tested prior to conducting the long-term condition analyses. At 6-month follow-up, multicollinearity was present on the ECBI and the PTC for mothers and on the PTC and PPC for fathers. Instead of using MANCOVA for these variables, univariate ANCOVAs were conducted on each subscale and an alpha of .05 was retained for the same rationale as described in section 4.3 (Jaccard & Guilamo-Ramos, 2002). Box’s M tests of equality of covariance matrices revealed no violations against the assumptions of variance-covariance matrices for the MANCOVAs and the scatterplots indicated no problems with linearity.

The specific assumptions for the ANCOVAs examining the long-term condition effects were also checked prior to conducting the analyses. The assumption of homogeneity of regression slopes was violated for the mothers PES Parenting Experience ANCOVA. As described previously, Field (2013) suggested that when this assumption is violated, findings should be interpreted with caution. Examination of the Levene’s tests indicated a violation on the DASS-21 for mothers and on the following scales for fathers: SDQ Total Difficulties, DASS-21, and PES Partner Support. When the results were examined using a more stringent alpha, there was only one difference in the interpretation of findings (for the mothers DASS- 21). However, an alpha level of .05 was retained for these ANCOVAs in order to minimise the risk of missing an intervention effect (Jaccard & Guilamo-Ramos, 2002). Inspection of the scatterplots indicated no problems with linearity.

Table 4.3 below shows the descriptive statistics for the outcome measures at pre- intervention and 6-month follow-up for mothers in each condition. Univariate F values, p values, and effect sizes (d) are also presented. The same information is provided for fathers in Table 4.4.

4.4.1 Mothers

Significant univariate condition effects for disruptive child behaviour on the ECBI Intensity and ECBI Problem subscales were again found at 6-month follow-up. Mothers in the multiple exemplar condition continued to report greater improvement in the intensity and

number of disruptive child behaviours between pre-intervention and 6-month follow-up when compared to mothers in the single exemplar condition. The condition effect was medium in size for the ECBI Problem subscale and small in size for the ECBI Intensity subscale. Furthermore, the univariate condition effects for ineffective parenting practices (PS) and parenting self-efficacy across behaviours (PTC Behavioural self-efficacy) were still significant at 6-month follow-up, with mothers in the multiple exemplar condition reporting greater improvements on these measures between pre-intervention and 6-month follow-up.

A significant univariate condition effect was now found at 6-month follow-up on the PTC Setting self-efficacy subscale. Mothers in the multiple exemplar condition reported significantly greater PTC Setting self-efficacy Total scores at 6-month follow-up after controlling for pre-intervention scores (small condition effect). Furthermore, significant univariate condition effects were also found on the measures of parental mental health (DASS- 21) and partner support (PES Partner Support). Mothers in the multiple exemplar condition reported greater improvement in their mental health and their perceptions of partner support at 6-month follow-up after controlling for pre-intervention levels of these measures. There were no significant multivariate condition effects for the PDR, F(2, 67) = 3.11, p = .052, or the PPC, F(2, 60) = 1.27, p = .298, and no significant univariate condition effects for the SDQ, PES Parenting Experience, and the RQI.

4.4.2 Fathers

For fathers, at 6-month follow-up no multivariate condition effect was found for disruptive child behaviour on the ECBI after controlling for pre-intervention scores, F(2, 53) = 1.63, p = .223, and there was no significant univariate condition effect on the measure of ineffective parenting practices. However, the effect for the multiple exemplar condition over the single exemplar condition was medium in size for the ECBI Problem subscale. For the PDR, no multivariate condition effect was found at 6-month follow-up for fathers, F(2, 51) = 2.93, p = .066, and no significant univariate condition effects were found on any of the other measures at 6-month follow-up. Although the multivariate condition effect was not significant for the PDR, effects were medium in size in favour of the multiple exemplar condition on both of the subscales.

4.4.3 Completer Analyses

The MANCOVAs and ANCOVAs were repeated to examine the long-term condition effects using only the sample of mothers and fathers who completed 6-month follow-up outcome measures. At 6-month follow-up, 24 (70.6%) and 33 mothers (80.5%) in the single exemplar and multiple exemplar conditions respectively completed outcomes measures. For

mothers, none of the significant long-term condition effects found among the ITT sample were significant among the completer sample. For fathers, 6-month follow-up outcomes measures were completed by 19 (70.4%) fathers in the single exemplar condition and 27 (87.1%) fathers in the multiple exemplar condition. There were no differences in the pre-intervention to 6- month follow-up condition effects obtained from the completer sample when compared to the ITT sample for fathers.

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Table 4.3 Descriptive Statistics and Univariate Effects for Condition for Mothers at 6-Month Follow-Up

Measure Single exemplar (N = 34) Multiple exemplar (N = 41) F condition p d Pre- intervention 6-month follow-up Pre- intervention 6-month follow-up M SD M SD M SD M SD

Child behaviour measures

ECBI Intensity Total (36-252) 150.10 30.51 131.46 33.23 145.53 22.24 115.75 24.22 4.95 .031 0.42

ECBI Problem Total (0-36) 19.37 6.23 15.48 8.17 19.40 5.55 11.88 6.67 4.73 .034 0.62

SDQ Total Difficulties (0-40) 15.16 5.89 12.72 7.10 15.11 5.94 11.80 5.87 0.64 .460 0.15

PDR Weekday Total (0-28)a 11.46 5.39 10.18 5.07 10.40 6.44 7.56 3.99 4.67 .039 0.26

PDR Weekend day Total (0-28)b 12.71 5.41 9.48 5.26 10.92 5.81 6.72 3.97 4.38 .046 0.17

Parenting measures

PS Total (1-7) 3.45 0.58 3.07 0.49 3.49 0.61 2.79 0.60 5.50 .023 0.54

PTC Behavioural self-efficacy Total (0-100) 69.33 22.97 78.90 15.31 64.06 20.07 85.67 10.75 8.62 .004 0.56

PTC Setting self-efficacy Total (0-100) 81.27 14.93 87.34 10.30 80.80 12.97 92.55 6.17 9.54 .003 0.41

PES Parenting Experience Total (5-25) 14.35 3.64 16.09 4.14 15.07 2.79 17.49 2.67 2.25 .163 0.21

PPC Extent Total (16-112)c 33.22 15.11 33.24 16.03 38.57 17.67 32.09 16.33 1.34 .256 0.40

PPC Problem Total (0-16)c 5.73 3.93 4.86 3.48 6.32 4.06 4.25 3.57 2.51 .125 0.30

Parent mental health measure

DASS-21 Total (0-63) 10.85 8.21 9.47 8.25 10.23 8.07 6.28 4.54 4.90 .031 0.32

Partner relationship measures

PES Partner Support Total (2-16)d 10.36 2.51 10.43 2.38 9.60 3.10 11.05 2.96 5.24 .036 0.49

RQI Total (6-45)e 32.32 9.29 31.44 9.89 32.09 10.20 34.80 9.11 4.66 .059 0.37

Note. F = univariate effect for condition, significant p values are bolded; d = effect size for condition; d 0.20 ≤ 0.49 = small, d 0.50 ≤ 0.79 = medium, d ≥ 0.80 = large.

a_{n = 33 for the single exemplar condition, n = 41 for the multiple exemplar condition.} b_{n = 33 for the single exemplar condition, n = 39-40 for the multiple exemplar condition.} c_{n = 29 for the single exemplar condition, n = 36 for the multiple exemplar condition.} d

n = 28-29 for the single exemplar condition, n = 35 for the multiple exemplar condition.

e_{n = 29 for the single exemplar condition, n = 35 for the multiple exemplar condition.}

Table 4.4 Descriptive Statistics and Univariate Effects for Condition for Fathers at 6-Month Follow-Up Measure Single exemplar (N = 27) Multiple exemplar (N = 31) F condition p d Pre- intervention 6-month follow-up Pre- intervention 6-month follow-up M SD M SD M SD M SD

Child behaviour measures

ECBI Intensity Total (36-252) 134.89 26.89 113.51 17.22 142.81 29.87 113.51 25.83 0.12 .742 0.28

ECBI Problem Total (0-36) 16.37 6.64 12.70 5.39 18.14 7.80 10.29 7.82 2.81 .107 0.58

SDQ Total Difficulties (0-40) 12.52 5.24 10.68 3.49 14.79 6.21 12.31 5.50 0.51 .501 0.11

PDR Weekday Total (0-28)a 8.73 4.81 8.24 4.05 10.90 6.83 6.16 3.83 5.62 .025 0.73

PDR Weekend day Total (0-28)b 8.78 4.72 8.33 4.12 10.17 6.58 6.81 3.62 3.35 .076 0.52

Parenting measures

PS Total (1-7) 3.33 0.54 2.99 0.64 3.32 0.73 2.78 0.63 2.10 .159 0.31

PTC Behavioural self-efficacy Total (0-100) 74.28 21.08 83.72 11.20 68.38 22.30 85.04 12.44 1.32 .258 0.33

PTC Setting self-efficacy Total (0-100) 86.84 9.45 89.81 6.82 82.50 11.65 90.17 9.01 2.36 .131 0.45

PES Parenting Experience Total (5-25) 17.07 3.85 18.15 2.77 15.81 3.39 18.00 2.19 0.71 .483 0.31

PPC Extent Total (16-112)b 32.19 16.19 26.23 8.28 38.19 18.92 34.14 15.43 3.85 .055 -0.11

PPC Problem Total (0-16)b 5.35 3.90 3.52 2.81 5.97 4.13 4.80 3.67 1.79 .204 -0.16

Parent mental health measure

DASS-21 Total (0-63) 7.59 6.79 7.37 4.97 11.73 10.10 9.73 9.19 0.19 .679 0.21

Partner relationship measures

PES Partner Support Total (2-16)c 10.74 2.70 11.90 1.68 10.53 2.49 11.24 2.59 1.38 .285 -0.17

RQI Total (6-45)b 33.62 8.47 35.01 6.23 33.41 8.69 33.19 9.84 0.75 .412 -0.19

Note. F = univariate effect for condition; d = effect size for condition; d 0.20 ≤ 0.49 = small, d 0.50 ≤ 0.79 = medium, d ≥ 0.80 = large.

a_{n = 25 for the single exemplar condition, n = 31 for the multiple exemplar condition.} b_{n = 26 for the single exemplar condition, n = 31 for the multiple exemplar condition.} c_{n = 26 for the single exemplar condition, n = 30-31 for the multiple exemplar condition.}