ADHD Diagnostic Scales: Which Test Is Best?

Megan Brooks

March 02, 2016

Two of the most commonly used scales in diagnosing attention-deficit/hyperactivity disorder (ADHD) are moderately sensitive and specific, but one may have the edge over the other, a new meta-analysis shows.

In comparing diagnostic performance of ADHD scales, investigators, led by Ling-Yin Chang, PhD, Taipei Medical University, in Taiwan, found that the Child Behavior Checklist–Attention Problem (CBCL-AP) scale, the Conners Rating Scale–Revised (CRS-R), and the Conners Abbreviated Symptom Questionnaire (ASQ) came out on top, but they write that the ASQ "may be the most effective diagnostic tool in assessing ADHD because of its brevity and high diagnostic accuracy."

The study was published in the March issue of Pediatrics.

More Informed Decision Making

There have been several comprehensive reviews of the CBCL-AP and the CRS-R, but the sensitivity, specificity, and diagnostic odds ratio of these tools, a measure indicative of their diagnostic performance, have rarely been examined.

"To the best of our knowledge, no meta-analyses have reported pooled estimates of the diagnostic accuracy of CBCL-AP and CRS-R," the researchers note.

For the study, the authors compared the performance of the CBCL-AP and the CRS-R for diagnosing ADHD in children. They reviewed data from 14 studies of the CBCL-AP and 11 studies of the CRS-R that were conducted in pediatric populations and that were compared with a defined reference standard.

Of the 11 Conners studies, one applied the Conners Parent Rating Scale–Revised Short Form (CPRS-R:S) alone; two applied the Conners Teacher Rating Scale–Revised Short Form (CTRS-R:S) alone; five applied the ASQ alone; and three applied both the CTRS-R:S and the CPRS-R:S.

The analysis showed pooled sensitivities of 0.77, 0.75, 0.72, and 0.83 for the CBCL-AP, the CPRS-R, the CTRS-R, and the ASQ, respectively, and pooled specificities of 0.73, 0.75, 0.84, and 0.84, respectively.

There was no difference in the diagnostic performance of the various scales, the authors report. They found heterogeneity in the specificity of the CBCL-AP, which was explained by study location, age of participants, and percentage of female participants.

"Our findings can help clinicians make more informed decisions regarding the selection of the most suitable rating scales for assessments," Dr Chang and colleagues conclude.

They note that many symptoms of ADHD are not always observed in clinical settings; therefore, information provided by both the CBCL and the CRS-R "can enhance clinicians' understanding of children's symptoms in different settings."

They also say that the ASQ may be the best tool, owing to its ease of use and its high diagnostic accuracy, but they recommend the CBCL "when more comprehensive assessments are required for detecting other comorbid conditions of ADHD, because the CBCL-AP can be applied together with other CBCL subscales. However, the moderate diagnostic values of CRS-R and CBCL reveal the importance of incorporating clinical examinations to eliminate other disorders and obtain information such as age of onset, intensity and pervasiveness of symptoms, and level of impairment during ADHD diagnosis," the investigators conclude.

Good, Not Great

In an accompanying editorial, William J. Barbaresi, MD, of Boston Children's Hospital and Harvard Medical School, writes that this study provides "important information about ADHD rating scales and draws much-needed attention to the critical role that rating scales play in the diagnosis and treatment of childhood ADHD."

Dr Barbaresi notes that the American Academy of Pediatrics' practice guideline for ADHD recommends use of the validated ADHD questionnaires for both the initial diagnosis and the monitoring of response to treatment.

Dr Barbaresi writes that a recent study shows that rating scales are used only about half the time during initial assessments and far less often in the first year after ADHD treatment is initiated by pediatricians to assess response to treatment, which he says is unfortunate.

Commenting on the findings for Medscape Medical News, Stephen V. Faraone, PhD, State University of New York Upstate Medical University, in Syracuse, said this analysis is "useful and well executed. The rating scales they mention are well known among mental health professionals but much less so among pediatricians, who are on the front line for the diagnosis and treatment of ADHD."

The interpretation of the results is "reasonable," Dr Faraone said, but he has "one quibble about the loose use of the term 'diagnosis.' For example, they describe the ASQ as 'an ideal tool for diagnosing ADHD.' I would have replaced 'diagnosing' with 'assessing' or 'screening for.'

"Rating scales are not to be used by themselves to diagnose the disorder. They are meant to supplement the diagnosis by a clinician by use prior to a clinical interview (ie, for screening) or after an interview (to collect additional data in unclear cases)," he explained.

Dr Faraone also noted that the accuracy of these scales is "good [but] not great. As one example, the specificity of the ASQ is estimated to be 84%. That means that 16% of youth without ADHD will be incorrectly classified as ADHD. That is okay if one is screening for the disorder, because those false positives will be weeded out by a clinical interview. But it is far from okay for a diagnostic procedure."

It is also important to note, Dr Faraone said, that the study only reviewed commercial pay-for-use scales. "There are several scales that are free, such as the Vanderbilt, SNAP [Swanson, Nolan and Pelham Teacher and Parent Rating Scale], and BASC [Behavior Assessment Scale for Children]. I would welcome a review of those scales as well," he said.

The study was supported by a grant from the Ministry of Science and Technology of the Republic of China. The authors, Dr Barbaresi, and Dr Faraone have disclosed no relevant financial relationships.

Pediatrics. 2016;137: e20152749. Abstract, Editorial


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