Objective: Conners Adult ADHD Rating Scale (CAARS) is among the valid questionnaires for evaluating Attention-Deficit/Hyperactivity Disorder in adults. The aim of this paper is to evaluate the validity of the estimation of missed answers in scoring the screening version of the Conners questionnaire, and to extract its principal components.
Method: This study was performed on 400 participants. Answer estimation was calculated for each question (assuming the answer was missed), and then a Kruskal-Wallis test was performed to evaluate the difference between the original answer and its estimation. In the next step, principal components of the questionnaire were extracted by means of Principal Component Analysis (PCA). Finally the evaluation of differences in the whole groups was provided using the Multiple Comparison Procedure (MCP).
Results: Findings indicated that a significant difference existed between the original and estimated answers for some particular questions. However, the results of MCP showed that this estimation, when evaluated in the whole group, did not show a significant difference with the original value in neither of the questionnaire subscales. The results of PCA revealed that there are eight principal components in the CAARS questionnaire.
Conclusion: The obtained results can emphasize the fact that this questionnaire is mainly designed for screening purposes, and this estimation does not change the results of groups when a question is missed randomly. Notwithstanding this finding, more considerations should be paid when the missed question is a critical one.
Key words: Attention deficit disorder with hyperactivity, Principal component analysis, Psychiatric status rating scale
Iran J Psychiatry 2010; 5:108-112
Attention Deficit / Hyperactivity Disorder (ADHD) is characterized as having inattentiveness, hyperactivity, and impulsivity. This disorder was primarily thought to be a problem limited to youth. However, in recent years, researchers have found that ADHD is often a chronic condition which persists into adulthood (1, 2). The available data suggest that between 30 and 70 percent of children with ADHD continue to manifest symptoms in adulthood (2-5). It is estimated that between 1 and 7 percent of the adult population experience ADHD symptoms (2-4).
The four most commonly used self-report measures (3) for ADHD are the Conners Adult ADHD Rating Scale (CAARS) (1, 6); the Wender Rating Scale (7); the Copeland Symptom Checklist (8); and the Brown Scale (9). These screening tools are not generally used for diagnostic purposes, as inattention, impulsivity, and volatile mood are features of several other psychiatric conditions. The screening forms are useful when a quick screen for ADHD symptoms is required.
The CAARS is a set of easily administered self-report questionnaires and observer-rated instruments which has been designed to assess symptoms related to ADHD in adults.
A main problem in self-report measures is the high probability of missing some questions by ADHD patients which can interfere with scoring the questionnaire. In this case, to score the questionnaire, the operator should complete the missed answer(s) through averaging the answers of other questions in that subscale and putting the result for the missed answer (1).
In this study, we evaluated the validity of the estimated missed answers to find out whether this estimation was valid and on which questions it could be used. We also extracted principal components of the screening version of the CAARS questionnaire.
Material and method
The CAARS is a suitable instrument for evaluating ADHD symptoms in adults. It utilizes a 4-point format in which respondents are asked to rate items pertaining to their problems.
The self-report screening form (CAARS-Self report: Screening Version, CAARS-S: SV) which was used in this study, has 30 items that assess ADHD symptoms according to the 4th edition of Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) (3). …