Diagnostic validity of early-onset obsessive-compulsive disorder in the Danish Psychiatric Central Register: findings from a cohort sample

Abstract

ObjectivesEmploying national registers for research purposes depends on a high diagnostic validity. The aim of the present study was to examine the diagnostic validity of recorded diagnoses of early-onset obsessive-compulsive disorder (OCD) in the Danish Psychiatric Central Register (DPCR).DesignReview of patient journals selected randomly through the DPCR.MethodOne hundred cases of OCD were randomly selected from DPCR. Using a predefined coding scheme based on the Children’s Yale Brown Obsessive Compulsive Scale (CYBOCS), experienced research nurse or child and adolescent psychiatrists assessed each journal to determine the presence/absence of OCD diagnostic criteria. The detailed assessments were reviewed by two senior child and adolescent psychiatrists to determine if diagnostic criteria were met.Primary outcome measurementsPositive predictive value (PPV) was used as the primary outcome measurement.ResultsA total of 3462 children/adolescents received an OCD diagnosis as the main diagnosis between 1 January 1995 and 31 December 2015. The average age at diagnosis was 13.21±2.89 years. The most frequent registered OCD subcode was the combined diagnosis DF42.2. Of the 100 cases we examined, 35 had at least one registered comorbidity. For OCD, the PPV was good (PPV 0.85). Excluding journals with insufficient information, the PPV was 0.96. For the subcode F42.2 the PPV was 0.77. The inter-rater reliability was 0.94. The presence of the CYBOCS in the journal significantly increased the PPV for the OCD diagnosis altogether and for the subcode DF42.2.ConclusionThe validity and reliability of International Classification of Disease 10th revision codes for OCD in the DPCR is generally high. The subcodes for predominant obsessions/predominant compulsions are less certain and should be used with caution. The results apply for both children and adolescents and for both older and more recent cases. Altogether, the study suggests that there is a high validity of the OCD diagnosis in the Danish National Registers.

The validity of child and adolescent depression diagnoses in the Danish psychiatric central research register

“…It could also be explained by Danish clinicians gaining more experience in using the ICD-10 criteria that were implemented in 1994. In contrast to the present study, studies examining the validity of hyperkinetic disorder 20 and OCD 19 diagnoses did not find a time trend in diagnostic validity. This difference might be caused by different analytical methods (dichotomous time variables in the hyperkinetic disorder study vs. a continuous time variable in the present study).…”

“…23 However, validity has been reported to be slightly higher for other child and adolescent psychiatric diagnoses in the DPCRR. The validity of early-onset obsessive-compulsive disorder (OCD) diagnoses was found to be 85% 19 and that of hyperkinetic disorder was 86.8%. 20 Another study validating the diagnosis of childhood autism reported a validity of 94% with even 97% meeting the criteria for any autism spectrum disorder (ASD).…”

“…[14][15][16][17] Furthermore, the existing studies are characterized by marked variation in methodology. [18][19][20][21] Most commonly, hospital records from the contact that led to assignment of the specific diagnosis have been reviewed to determine the extent to which the documented observations justified the assigned diagnosis. This approach was used in studies of child and adolescent psychiatric disorders in the DPCRR relating to childhood autism, 22 early-onset obsessive-compulsive disorder, 19 early-onset schizophrenia 23 and hyperkinetic disorder.…”

“…[18][19][20][21] Most commonly, hospital records from the contact that led to assignment of the specific diagnosis have been reviewed to determine the extent to which the documented observations justified the assigned diagnosis. This approach was used in studies of child and adolescent psychiatric disorders in the DPCRR relating to childhood autism, 22 early-onset obsessive-compulsive disorder, 19 early-onset schizophrenia 23 and hyperkinetic disorder. 20 No studies have yet examined the validity of depression diagnoses available in a national patient register that were assigned to children and adolescents.…”

Parental Age and Differential Estimates of Risk for Neuropsychiatric Disorders: Findings From the Danish Birth Cohort

“…Although the Danish national healthcare system provides psychiatric care to all citizens at no cost, and this structure supports broad inclusion of the clinical population within the registries, those with subthreshold clinical disorders or those who do not seek treatment would not be included herein. Although the validity for childhood autism, schizophrenia and OCD in Danish registers is over 90%, [73][74][75] and 83% for ADHD, 76 TS/CT diagnoses have yet to be validated. Of note, such validation has been achieved in a similar Swedish health care system 77 .…”