Self-reported disability pension (DP) and sickness absence are commonly used in epidemiological and other studies as a measure of exposure or even as an outcome. The aims were (1) to compare such self-reports with national register information in order to evaluate the validity of self-reported DP and sickness absence, and (2) to estimate the concordance of reporting behaviour in different twin zygosity groups, also by sex.
All Swedish twins born 1933-1958 who participated in the Screening Across the Lifespan Twin study (SALT) 1998-2003, were included (31,122 individuals). The self-reported DP and long-term sickness absence (LTSA) at the time of interview was compared to the corresponding register information retrieved from the National Social Insurance Agency by calculating the proportions of agreements, kappa, sensitivity, specificity, concordance rates, and chi-square test, to evaluate construct validity.
The proportions of overall agreement were 96% and specificity 99% for both DP and LTSA, while the sensitivity was 70% for DP and 45% for LTSA. Kappa estimates were 0.76 for DP, and 0.58 for LTSA. The proportions of positive agreement were 64% for DP and 42% for LTSA. No difference in response style was found between zygosity groups among complete twin pairs for DP and LTSA. Results were similar for women and men and across age. Kappa estimates for DP differed somewhat depending on years of education, 0.68 (college/university) vs. 0.77 (less than 13 years in school) but not for LTSA.
Self-reported DP data may be very useful in studies when register information is not available, however, register data is preferred especially for LTSA. The same degree of twin similarity was found for truthful self-report of DP and LTSA in both monozygotic and dizygotic twin pairs. Thus, the response style was not influenced by genetic factors. One consequence of this would be that when estimating the relative importance of genetic and environmental effects from twin models, heritability estimates would not be biased.
The usefulness of cases diagnosed in administrative registers for research purposes is dependent on diagnostic validity. This study aimed to investigate the validity and inter-rater reliability of recorded diagnoses of tic disorders and obsessive-compulsive disorder (OCD) in the Swedish National Patient Register (NPR).
Chart review of randomly selected register cases and controls.
100 tic disorder cases and 100 OCD cases were randomly selected from the NPR based on codes from the International Classification of Diseases (ICD) 8th, 9th and 10th editions, together with 50 epilepsy and 50 depression control cases. The obtained psychiatric records were blindly assessed by 2 senior psychiatrists according to the criteria of the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) and ICD-10.
Positive predictive value (PPV; cases diagnosed correctly divided by the sum of true positives and false positives).
Between 1969 and 2009, the NPR included 7286 tic disorder and 24,757 OCD cases. The vast majority (91.3% of tic cases and 80.1% of OCD cases) are coded with the most recent ICD version (ICD-10). For tic disorders, the PPV was high across all ICD versions (PPV=89% in ICD-8, 86% in ICD-9 and 97% in ICD-10). For OCD, only ICD-10 codes had high validity (PPV=91-96%). None of the epilepsy or depression control cases were wrongly diagnosed as having tic disorders or OCD, respectively. Inter-rater reliability was outstanding for both tic disorders (?=1) and OCD (?=0.98).
The validity and reliability of ICD codes for tic disorders and OCD in the Swedish NPR is generally high. We propose simple algorithms to further increase the confidence in the validity of these codes for epidemiological research.
The Autism-Tics, AD/HD, and other Comorbidities (A-TAC) inventory is used in epidemiological research to assess neurodevelopmental problems and coexisting conditions. Although the A-TAC has been applied in various populations, data on retest reliability are limited. The objective of the present study was to present additional reliability data. The A-TAC was administered by lay assessors and was completed on two occasions by parents of 400 individual twins, with an average interval of 70 days between test sessions. Intra- and inter-rater reliability were analysed with intraclass correlations and Cohen's kappa. A-TAC showed excellent test-retest intraclass correlations for both autism spectrum disorder and attention deficit hyperactivity disorder (each at .84). Most modules in the A-TAC had intra- and inter-rater reliability intraclass correlation coefficients of > or = .60. Cohen's kappa indi- cated acceptable reliability. The current study provides statistical evidence that the A-TAC yields good test-retest reliability in a population-based cohort of children.
The Child and Adolescent Twin Study in Sweden (CATSS) is an ongoing longitudinal twin study targeting all twins born in Sweden since July 1, 1992. Since 2004, parents of twins are interviewed regarding the children's somatic and mental health and social environment in connection with their 9th or 12th birthdays (CATSS-9/12). By January 2010, 8,610 parental interviews concerning 17,220 twins had been completed, with an overall response rate of 80%. At age 15 (CATSS-15) and 18 (CATSS-18), twins and parents complete questionnaires that, in addition to assessments of somatic and mental health, include measures of personality development and psychosocial adaptation. Twin pairs in CATSS-9/12 with one or both twins screening positive for autism spectrum disorders, attention deficit/hyperactivity disorder, tic disorders, developmental coordination disorder, learning disorders, oppositional defiant disorder, conduct disorder, obsessive-compulsive disorder, and/or eating problems have been followed with in-depth questionnaires on family, social environment and personality, and subsequently by clinical assessments at age 15 together with randomly selected population controls, including 195 clinically assessed twin pairs from the first 2 year cohorts (CATSS-15/DOGSS). This article describes the cohorts and study groups, data collection, and measures used. Prevalences, distributions, heritability estimates, ages at onset, and sex differences of mental health problems in the CATSS-9/12, that were analyzed and found to be overall comparable to those of other clinical and epidemiological studies. The CATSS study has the potential of answering important questions on the etiology of childhood mental health problems and their role in the development of later adjustment problems.
Although bipolar disorder is associated with various adverse health outcomes, the relationship with violent crime is uncertain.
To determine the risk of violent crime in bipolar disorder and to contextualize the findings with a systematic review.
Longitudinal investigations using general population and unaffected sibling control individuals.
Population-based registers of hospital discharge diagnoses, sociodemographic information, and violent crime in Sweden from January 1, 1973, through December 31, 2004.
Individuals with 2 or more discharge diagnoses of bipolar disorder (n = 3743), general population controls (n = 37 429), and unaffected full siblings of individuals with bipolar disorder (n = 4059).
Violent crime (actions resulting in convictions for homicide, assault, robbery, arson, any sexual offense, illegal threats, or intimidation).
During follow-up, 314 individuals with bipolar disorder (8.4%) committed violent crime compared with 1312 general population controls (3.5%) (adjusted odds ratio, 2.3; 95% confidence interval, 2.0-2.6). The risk was mostly confined to patients with substance abuse comorbidity (adjusted odds ratio, 6.4; 95% confidence interval, 5.1-8.1). The risk increase was minimal in patients without substance abuse comorbidity (adjusted odds ratio, 1.3; 95% confidence interval, 1.0-1.5), which was further attenuated when unaffected full siblings of individuals with bipolar disorder were used as controls (1.1; 0.7-1.6). We found no differences in rates of violent crime by clinical subgroups (manic vs depressive or psychotic vs nonpsychotic). The systematic review identified 8 previous studies (n = 6383), with high heterogeneity between studies. Odds ratio for violence risk ranged from 2 to 9.
Although current guidelines for the management of individuals with bipolar disorder do not recommend routine risk assessment for violence, this assertion may need review in patients with comorbid substance abuse.
Comment In: Evid Based Ment Health. 2011 Feb;14(1):1721266614
BACKGROUND: Reliable, valid, and easy-to-administer instruments to identify possible caseness and to provide proxies for clinical diagnoses are needed in epidemiological research on child and adolescent mental health.The aim of this study is to provide further validity data for a parent telephone interview focused on Autism--Tics, Attention-deficit/hyperactivity disorder (AD/HD), and other Comorbidities (A-TAC), for which reliability and preliminary validation data have been previously reported. METHODS: Parents of 91 children clinically diagnosed at a specialized Child Neuropsychiatric Clinic, 366 control children and 319 children for whom clinical diagnoses had been previously assigned were interviewed by the A-TAC over the phone. Interviewers were blind to clinical information. Different scores from the A-TAC were compared to the diagnostic outcome. RESULTS: Areas under ROC curves for interview scores as predictors of clinical diagnoses were around 0.95 for most disorders, including autism spectrum disorders (ASDs), attention deficit/hyperactivity disorder (AD/HD), tic disorders, developmental coordination disorders (DCD) and learning disorders, indicating excellent screening properties. Screening cut-off scores with sensitivities above 0.90 (0.95 for ASD and AD/HD) were established for most conditions, as well as cut-off scores to identify proxies to clinical diagnoses with specificities above 0.90 (0.95 for ASD and AD/HD). CONCLUSIONS: The previously reported validity of the A-TAC was supported by this larger replication study using broader scales from the A-TAC-items and a larger number of diagnostic categories. Short versions of algorithms worked as well as larger. Different cut-off levels for screening versus identifying proxies for clinical diagnoses are warranted. Data on the validity for mood problems and oppositional defiant/conduct problems are still lacking. Although the A-TAC is principally intended for epidemiological research and general investigations, the instrument may be useful as a tool to collect information in clinical practice as well.
OBJECTIVE: To compare telephone interview screening for child psychiatric/neuropsychiatric disorders using the inventory of Autism-Tics, Attention deficit/hyperactivity disorder (AD/HD) and other Comorbidities (A-TAC) with results from the Child Behavior Checklist (CBCL). BACKGROUND: The A-TAC is a parent telephone interview focusing on autism spectrum disorders (ASDs) and co-existing problems, developed for lay interviewers. SUBJECTS AND METHODS: A-TAC telephone interviews and CBCL questionnaires were obtained from parents of 106 Swedish twin pairs aged 9 and 12 years. RESULTS: Correlations between A-TAC modules and CBCL scales aimed at measuring similar concepts were generally significant albeit modest, with correlation coefficients ranging from 0.30 through 0.55. CONCLUSION: The A-TAC has convergent validity with the CBCL in several problem areas, but the A-TAC also provides more detailed and specific assessments of ASD symptoms and related neuropsychiatric problems.
RefSource: Nord J Psychiatry. 2010 May 4;64(3):146