Identification of Latent classes
The accelerated flattening of the Log Likelihood and BIC values in the four class model, the decrease in entropy the non-significant CI for the LMT-IRT test for class 5 and the conceptual composition of the four class model suggested an appropriate solution to identifying meaningful classes of mental health symptoms, resulting in a four class model that had configural and structural similarity for both waves (Table 1).
Table 1 Model Fit
Wave 1
C
|
LL
|
Replicated
|
Parameters
|
AIC
|
BIC
|
SSABIC
|
LMR-LRT (p)
|
Entropy
|
2
|
-90182.722
|
YES
|
41
|
180447.445
|
180736.665
|
180606.374
|
(p <0.0000)
|
.745
|
3
|
-88503.928
|
YES
|
62
|
177131.857
|
177569.214
|
177372.190
|
(p<0.0000)
|
.736
|
4
|
-87566.067
|
YES
|
83
|
175298.633
|
175883.628
|
175619.869
|
(p<0.0000)
|
.717
|
5
|
-87250.496
|
YES
|
104
|
174708.993
|
175442.625
|
175113.132
|
(p<0.0827)
|
.692
|
Wave 2
C
|
LL
|
Replicated
|
Parameters
|
AIC
|
BIC
|
SSABIC
|
LMR-LRT (p)
|
Entropy
|
2
|
-74265.966
|
YES
|
41
|
148613.931
|
148897.886
|
148767.596
|
(p <0.0000)
|
.767
|
3
|
-72680.471
|
YES
|
62
|
145484.942
|
145914.336
|
145717.313
|
(p<0.0000)
|
.763
|
4
|
-71780.622
|
YES
|
83
|
143727.244
|
144302.079
|
144038.323
|
(p<0.0000)
|
.748
|
5
|
-71527.533
|
YES
|
104
|
143263.066
|
143988.341
|
143652.851
|
(p<0.6654)
|
.757
|
C = classes; LL = log-likelihood; AIC = Akaike Information Criterion; BIC = Bayesian Information Criterion; LMR-LRT = Lo– Mendell–Rubin Likelihood Ratio Test; p = p value.
Classes: Class 1 - High Risk of Emotional and Behavioural Difficulties (HEBD), had moderate to high probabilities of behavioural difficulties, namely hyperactivity, inattentiveness, disobedience, tantrums, lying and emotional difficulties, somatic illnesses, worry, nervousness, fearfulness, unhappiness, solitary playing, bullying and better adult than peer relationships.
Class 2- High Risk of Emotional Difficulties (HED), had moderate to high probabilities of somatic illnesses, worry, fear, nervousness, solitary play and moderate probabilities of tantrums.
Class 3- High Risk of Behavioural Difficulties (HBD), had moderate to high probabilities of hyperactivity, inattentiveness, disobedience and tantrums with low probabilities of emotional difficulties.
Class 4 - Low Risk of Emotional and Behavioural Difficulties (LEBD), presented with low probabilities of emotional and behavioural difficulties. (Fig.2). See Table S1a/b/c (supplementary materials) for item responses.
Latent Transition Analysis
LTA was conducted next to examine rates of transitions across classes from age 9 to 13 years (Fig.3). The LEBD class had the highest stability rate with a small proportion transitioning to the high risk classes. The HEBD class had the lowest stability rate, with transitions mostly to the HED and HBD class with a small proportion transitioning to the LEBD Class. The HED class and HBD class had moderate to high rates of stability with transitions occurring mostly to the LEBD class. (Table 2).
Table 2 Probability and Transition Matrix without covariates
Latent Classes
|
Wave 1 (C1)
|
HEBD (13yrs)
|
HED (13yrs)
|
HBD (13yrs)
|
LEBD (13yrs)
|
Wave 2 (C2)
|
HEBD (9yrs)
|
.173
|
0.557
|
0.140
|
0.283
|
0.018
|
.132
|
HED (9yrs)
|
.233
|
0.046
|
0.595
|
0.060
|
0.298
|
.187
|
HBD (9yrs)
|
.313
|
0.072
|
0.039
|
0.678
|
0.211
|
.293
|
LEBD (9yrs)
|
.281
|
0.011
|
0.044
|
0.060
|
0.886
|
.388
|
Bold values indicate probability of remaining in the same class, wave 1 (9 years), wave 2 (age 13 years).
|
Probability and Transition Matrix with covariates
Latent Classes
|
Time 1 (C1)
|
HEBD (13yrs)
|
HED (13yrs)
|
HBD (13yrs)
|
LEBD (13yrs)
|
Time 2 (C2)
|
EBD (9yrs)
|
.173
|
0.517
|
0.165
|
0.293
|
0.025
|
.130
|
ED (9yrs)
|
.246
|
0.044
|
0.569
|
0.081
|
0.305
|
.194
|
BD (9yrs)
|
.297
|
0.068
|
0.044
|
0.669
|
0.211
|
.293
|
LEBD (9yrs)
|
.283
|
0.010
|
0.046
|
0.066
|
0.879
|
.388
|
Bold values indicate probability of remaining in the same class, wave 1 (9 years), wave 2 (age 13 years).
|
Risk Factors on Transition Probabilities
Bullying, dislike of teacher, dislike of school, parent conflict and socio-economic status did not affect movement between classes whilst parental depression and problems at home that affect school participation at 9 years significantly affected transitions. Children in the HED and HBD classes with reports of parental depression had higher odds of transitioning to the HEBD class at 13 years compared to those who remained, OR = 2.568 (1.224, 5.390), OR =1.835 (1.089, 5.094),
Children who transitioned from the HEBD class to the HED, HBD or LEBD classes at 13 years had significantly lower odds of having problems at home affecting school participation compared to those who remained, OR = 0.155 (0.031, 0.775), OR = 0.525 (0.291, 0.946), OR = 0.281 (0.094, 0.842) respectively. Conversely, children who transitioned from the HED and LEBD classes to the HEBD class had significantly higher odds of having problems at home affecting school participation OR= 6.435 [1.290, 32.101], OR = 3.560 [1.188, 10.670]. These results indicate that problems at home that affect school participation and parental depression can negatively impact developmental trajectories of emotional and behavioural difficulties between 9 years and 13 years.
Females had significantly higher odds of transitioning from the HEBD and HBD class to the HED class at 13 years OR = 2.004 (1.295, 3.101), OR = 2.045 (1.402, 2.983), indicating that females are more likely than males to transition away from behavioural difficulties. There was also higher odds of females transitioning from the HED class to the LEBD class OR = 1.533 [1.142, 2.058]. (See supplementary Table S2 for transition probabilities).
Stability on Outcomes
Children who remained in The HEBD and HED classes compared to those who remained in the LEBD class were three times more likely to be chronically absent at 13 years, OR = 2.670 (1.231, 5.788), OR = 2.844 (1.400, 5.775). Children who remained in the HEBD and BD classes were 5 times more likely to report have truanted at 13 years compared to those remaining in the LEBD class OR = 5.598 (3.121, 10.043), OR = 4.600 (2.565, 8.24) respectively. Children remaining in the HED class did not have significant odds of having truanted and children remaining in the HBD Class did not have greater odds of chronic absenteeism These results indicate greater odds for chronic absenteeism for children experiencing stability of emotional difficulties and greater odds of truancy for children experiencing stability of behavioural difficulties. Children experiencing stability of co-morbid symptoms had greater odds of chronic absenteeism and truancy (Table 5).
Table 3 OR for Chronic Absenteeism and Have Truanted for stability
Stability
|
OR Chronic Absenteeism
95% CI
Est. S.E Lower Upper
|
OR Have Truanted
95% CI
Est. S.E Lower Upper
|
Stability in HEBD compared to
stability in HED class
stability in HBD class
stability in LEBD class
|
0.939(.36) (0.441, 1.998)
1.580(.67) (0.684, 3.653)
2.670(1.05) (1.231, 5.788)
|
4.223(1.8) (1.778, 10.028)
1.217(.35) (0.685, 2.163)
5.598(1.6) (3.121, 10.043)
|
Stability in HED compared to
Stability in HBD class
Stability in LEBD class
|
1.683(0.5) (0.845, 3.354)
2.844(1.02) (1.400, 5.775)
|
0.288(0.124) (0.109, 0.816)
1.326 (0.5) (0.547, 3.214)
|
Stability in HBD compared to
Stability in LEBD class
|
1.682(0.6) (0.836, 3.412)
|
4.600 (0.05) (2.565, 8.24)
|
Transitions on Outcomes
Odds Ratio was also calculated to compare the odds of chronic absenteeism and/or have truanted for children who leave one group compared to those who remain. No significant OR for chronic absenteeism was found for any group leaving one class compared to those who remained suggesting that mental health at 9 years had a greater effect on chronic absenteeism at 13 years than the class status transitioned to (Table 6). Transitions did affect the outcome Have Truanted for children moving between groups. Children who transitioned from the HBD to the HED class had significantly lower odds of reporting have truanted, OR = 0.233 (0.082, 0.662). Children who remained in the HEBD group were 6 times more like to report having truanted compared to those who transitioned to the HED and 10 times more likely than those who moved to the LEBD class OR = 6.893 (2.620, 18.136), OR = 10.177 (4.639, 22,327). Children who remained in the HED class were significantly less likely to truant compared to those who moved to the HBD class, OR = 0.233 (0.082,0.662).
The results indicate that children with emotional difficulties at 9 years were more likely to be absent with their parents knowledge at 13 years whilst children with behavioural difficulties at 9 years or who later develop behavioural difficulties were at risk of truancy. The children in the HEBD had significantly high odds of chronic absenteeism and have truanted indicating that children with co-morbid symptoms have a greater risk of SAPs.
Table 4 OR for Chronic Absenteeism and Have Truanted for Class Transitions.
Transitions
|
OR Chronic Absenteeism
95% CI
Est. S.E Lower Upper
|
OR Have Truanted
95% CI
Est. S.E Lower Upper
|
Remaining in the HEBD class compared to
transitioning from HEBD to ED class
Remaining in the HEBD class compared to
transitioning from HEBD to BD class
Remaining in the HEBD class compared to
transitioning from HEBD to LEBD class
Transitioning from the HED to HEBD class
compared to remaining in the HED class
Remaining in the HED class compared to
transitioning from the HED to HBD class
Remaining in the HED class compared to
transitioning from the HED to LEBD class
Transitioning from the HBD to HEBD class
compared to remaining in the HBD to HBD
Transitioning from the HBD to HED class
compared to remaining in the HBD class
Remaining in the BD class compared to
transitioning from the BD to LEBD
Transitioning from the LEBD to HED class
compared to remaining in the LEBD class
Transitioning from the LEBD to HBD class
compared to remaining in the LEBD
|
0.901 (0.77) (0.166, 4.886)
0.825(0.49) (0.256, 2.660)
1.857(1.41) (0.418, 8.256)
0.901(0.767) (0166, 4,866)
0.915(0.515) (0.304, 2.755)
2.061(0.88) (0.892, 4.762)
0.825(0.49) (0.256, 2.660)
0.915(0.51) (0.304, 2,755)
2.522(1.01) (0.935, 5.424)
2.016(0.8) (0.892, 4.762)
2.522(1.01) (0.935, 5.424)
|
6.893 (3.4) (2.620, 18.136)
1.603(0.47) (0.897, 2.865)
10.177(4.80) (4.639, 22,327)
0.613 (0.24) (0,283, 1.326)
0.233 (0.12) (0.082,0.662)
1.476 (0.82) (0.495,4,407)
0.759(0.25) (0.392, 1.472)
0.233(0.12) (0.082,0.662)
6.349(2.3) (3.081,13.085)
1.476(.82) (0.495, 4.407)
6.349(2.3) (3.081,13.085)
|
Bold values indicate significant OR’s for Chronic Absenteeism /Truancy