This is possibly a problem with select comorbidities. The pooled prevalence rates (across adult and paediatric studies) have wide confidence intervals for OCRDs, varying from <5 to >25% for any OCRD; <1–>6% for BDD, and ~1–>7% for Trichotillomania. If we consider only studies on adults, the confidence intervals widen, for any OCRD varying between ~6 and >30%; for BDD <1–>7%; for trichotillomania between ~1 and >10%. Wide confidence intervals were also seen for three comorbidities in the paediatric sub-group—MDD [17.1% (95% CI 6.3–31.6)], Panic disorder [6.1% (95% CI 0.5–16.4)], and ODD [12.5% (95% CI 2.3–28.7)]. Therefore, the pooled prevalence rates for these comorbid disorders score low in terms of precision.
