In contrast, we found significant effects for intervention programs offering parent training, regardless whether additional support is provided or not.
There were both positive and negative effects for intervention groups, but only a few were significant (see Table 4).
The dichotomised responses on the five point Likert scale to the treatment satisfaction question will be analysed by means of a generalised linear mixed model with logit link, fixed effects for intervention and baseline pain severity, and random physiotherapist effects.
Given the fact that some studies show a better effect for interventions with at least a low level of guidance compared to unguided interventions [ 46- 48], this strategy might be a promising approach to encourage high treatment adherence.
Eight of the 12 studies that tested the long-term effects of an intervention found significant effects for tailoring interventions compared to no intervention [ 31, 34, 65, 79] or generic health education [ 24, 32, 80, 81].
The lack of sustained treatment effects for existing interventions suggests that an intervention that focuses on sustained environmental enrichment through enhanced parenting practices may be beneficial.
The lack of sustained treatment effects for existing interventions suggests that a novel intervention that specifically addresses sustainability of effect may be beneficial.
Similarly, it may not be possible to identify statistically significant treatment effects, even for interventions known to be effective, when multiple morbidities are present.
After adjustment for confounders and clustering effects, statistical effects persisted for intervention community in the rate of decline (P<0.05, table 3 and fig 3).
