Pediatric Attention Disorders Diagnostic Screener
Encyclopedia
The Pediatric Attention Disorders Diagnostic Screener (PADDS), created by Dr. Thomas K. Pedigo and Kenneth L. Pedigo, is a suite of computer administered neuropsychological tests of attention
and executive functioning. The PADDS is used in the diagnosis of Attention Deficit Hyperactivity Disorder (ADHD) in children between the ages of 6 to 12 years. The PADDS software program represents a multi-dimensional, evidence-based approach to ADHD assessment. (Reddy, L. A., Fumari, G., Pedigo, T. K., Scott, V. B., Jr. 2008) Consisting of the Computer Administered Diagnostic Interview (CADI), the Swanson, Nolan, and Pelham—IV (SNAP-IV)
Parent rating scale
and Teacher rating scale, and three computer administered objective measures called the Target Tests of Executive Functioning (TTEF). The actuarial / statistical reporting functions make available an automatically calculated predictive index for scoring and reporting.This method uses Bayesian probability
to calculate diagnostic likelihood ratio
, which are then graphed on a Nomogram
to provide incremental validity when combining results from multiple measures so that each unique data source can be allowed to contribute to (or detract from, as the case may be) the prediction (Cumulative probability) of the diagnosis.(Frazier & Youngstrom; 2006)
The results are also given in a more traditional, normalized, relative Standard score
, T-score, Z-Score, and Percentile rank
format for comparison to the non-clinical reference group
.
It is a complicated neurodevelopmental psychiatric disorder and has an estimated range of occurrence of 2 to 3 percent of the school population and up to 10 percent in other settings. Thus, on average a minimum of at least one child with ADHD and executive functioning disorders is in each classroom in American schools. (Reddy et al.) (Rowland, Leswesne, & Abramowitz, 2002)
indicated that prevalence rates for ADHD vary markedly based on presenting symptoms, different assessment approaches used, and the various settings in which the child was tested. A lack of a consensus on what constitutes the core set of symptoms for ADHD complicates and confounds the screening and assessment process (Brown, 2002).
Due to these concerns regarding prevalence rates of ADHD, the American Academy of Pediatrics (AAP, 2000) and the National Institute of Health (NIH, 1998) have stressed the need to develop new standardized, evidence-based assessments that have strong psychometric properties, and are easily administered in schools and other clinical settings.
The major considerations guiding the development of the PADDS is integrating an updated construct of ADHD assessment, while focusing on ways to enhance diagnostic accuracy in an efficient manner.
Clinical testing of the PADDS Target Tests of Executive Functioning was conducted on one of the largest samples of age specific, ADHD and non-ADHD subjects collected, with 725 children (240 females and 485 males) age 6 to 12 years (M = 8.63, SD = 1.72) split approximately evenly between those diagnosed with ADHD (n = 395) and age matched Non-ADHD/ Typical peers (n = 330). Data were collected in seven states from a total of 10 data collection sites. Institutional Review Board
(IRB) approval for the overall project was established through Armstrong Atlantic State University
in Savannah, Georgia. All research sites included specialty ADHD assessment centers, each with independent IRB oversight, in Illinois, Georgia, Idaho, New Jersey, Tennessee, California, and Florida. Pedigo, Pedigo & Scott (2008).
The SNAP-IV rating scales offer categorical and dimensional input across the 18 core diagnostic items from the Diagnostic and Statistical Manual of Mental Disorders DSM-IV Fourth Edition-Revised. Each item is rated on a 4-point Likert scale
for severity. These behavioral criteria when used in the ascribed manner have produced reliable sensitivity and specificity in identifying ADHD cases relative to non-clinical reference groups. (Power, T. J., Andrews, T. J., Eiraldi, R. B., Doherty, B. J., Ikeda, M. J., DuPaul, G. J., & Landau, S.; 1998)
(Zolotor, A. J., & Mayer, J. ; 2004)
, sequential memory and procedural memory
functions, and help provide an objective assessment of a subject’s ability to employ various but not all executive processes such as planning, attending, organizing input, storing and retrieving information, modulating emotions and sustaining effort. These task demands have been consistently identified as areas of difficulty for children known to have ADHD.(Russell Barkley
; 1997)
Specific requirements for task completion include among others:
Attention to detail, avoiding distraction, maintenance of effort or persistence, holding information in mind through the use of metacognition
, feedback, and emotional regulation while developing a response to changes in novel stimuli.
Specific requirements for task completion include among others:
Attention to detail, avoiding distraction, maintenance of effort or persistence, holding information in mind through the use of metacognition, feedback, and emotional regulation during the initiation and follow through of a response to complex sequences while remaining sensitive to changes in novel stimuli.
Specific requirements for task completion include among others:
Attention to detail, maintaining divided attention, holding information in mind, maintenance of effort or persistence and emotional regulation while completing complex two and three step instructions.
. The inputs are displayed in a real time format via a computer generated Nomogram presenting an individual and an overall predictive index of likelihood ratios establishing evidence for or against a diagnosis. Results are likewise presented in a normalized, relative Standard score, T-score, Z-Score, and Percentile rank format for comparison to the non-clinical reference group
.
The Nomographic display of the individual and cumulative inputs are evaluated stepwise via the calculation of likelihood ratios applied incrementally with a Fagan's Nomogram,(Fagan TJ ;1975) to produce an overall predictive index beginning with a calculated base rate, and combining the results of the other measures, in either an additive or subtractive manner, to provide a post-test probability. When these components are used in conjunction with clinical judgment they have proven to be highly effective for consideration of diagnosis, in highlighting and documenting a need for further evaluation or actions, and may allow the clinician to evaluate their own diagnostic practices and effectiveness over time.
The PADDS is published by and available from Targeted Testing, Inc. and other major psychological test publishers.
Attention
Attention is the cognitive process of paying attention to one aspect of the environment while ignoring others. Attention is one of the most intensely studied topics within psychology and cognitive neuroscience....
and executive functioning. The PADDS is used in the diagnosis of Attention Deficit Hyperactivity Disorder (ADHD) in children between the ages of 6 to 12 years. The PADDS software program represents a multi-dimensional, evidence-based approach to ADHD assessment. (Reddy, L. A., Fumari, G., Pedigo, T. K., Scott, V. B., Jr. 2008) Consisting of the Computer Administered Diagnostic Interview (CADI), the Swanson, Nolan, and Pelham—IV (SNAP-IV)
Parent rating scale
Rating scale
A rating scale is a set of categories designed to elicit information about a quantitative or a qualitative attribute. In the social sciences, common examples are the Likert scale and 1-10 rating scales in which a person selects the number which is considered to reflect the perceived quality of a...
and Teacher rating scale, and three computer administered objective measures called the Target Tests of Executive Functioning (TTEF). The actuarial / statistical reporting functions make available an automatically calculated predictive index for scoring and reporting.This method uses Bayesian probability
Bayesian probability
Bayesian probability is one of the different interpretations of the concept of probability and belongs to the category of evidential probabilities. The Bayesian interpretation of probability can be seen as an extension of logic that enables reasoning with propositions, whose truth or falsity is...
to calculate diagnostic likelihood ratio
Likelihood ratios in diagnostic testing
In evidence-based medicine, likelihood ratios are used for assessing the value of performing a diagnostic test. They use the sensitivity and specificity of the test to determine whether a test result usefully changes the probability that a condition exists.-Calculation:Two versions of the...
, which are then graphed on a Nomogram
Nomogram
A nomogram, nomograph, or abac is a graphical calculating device developed by P.E. Elyasberg, a two-dimensional diagram designed to allow the approximate graphical computation of a function: it uses a coordinate system other than Cartesian coordinates...
to provide incremental validity when combining results from multiple measures so that each unique data source can be allowed to contribute to (or detract from, as the case may be) the prediction (Cumulative probability) of the diagnosis.(Frazier & Youngstrom; 2006)
The results are also given in a more traditional, normalized, relative Standard score
Standard score
In statistics, a standard score indicates how many standard deviations an observation or datum is above or below the mean. It is a dimensionless quantity derived by subtracting the population mean from an individual raw score and then dividing the difference by the population standard deviation...
, T-score, Z-Score, and Percentile rank
Percentile rank
The percentile rank of a score is the percentage of scores in its frequency distribution that are the same or lower than it. For example, a test score that is greater than 75% of the scores of people taking the test is said to be at the 75th percentile....
format for comparison to the non-clinical reference group
Reference group
A reference group is a concept referring to a group to which an individual or another group is compared.Sociologists call any group that individuals use as a standard for evaluating themselves and their own behavior a reference group....
.
PADDS history and development
One of the most commonly diagnosed childhood disorders referred to mental health clinicians is ADHD.It is a complicated neurodevelopmental psychiatric disorder and has an estimated range of occurrence of 2 to 3 percent of the school population and up to 10 percent in other settings. Thus, on average a minimum of at least one child with ADHD and executive functioning disorders is in each classroom in American schools. (Reddy et al.) (Rowland, Leswesne, & Abramowitz, 2002)
indicated that prevalence rates for ADHD vary markedly based on presenting symptoms, different assessment approaches used, and the various settings in which the child was tested. A lack of a consensus on what constitutes the core set of symptoms for ADHD complicates and confounds the screening and assessment process (Brown, 2002).
Due to these concerns regarding prevalence rates of ADHD, the American Academy of Pediatrics (AAP, 2000) and the National Institute of Health (NIH, 1998) have stressed the need to develop new standardized, evidence-based assessments that have strong psychometric properties, and are easily administered in schools and other clinical settings.
The major considerations guiding the development of the PADDS is integrating an updated construct of ADHD assessment, while focusing on ways to enhance diagnostic accuracy in an efficient manner.
Clinical testing of the PADDS Target Tests of Executive Functioning was conducted on one of the largest samples of age specific, ADHD and non-ADHD subjects collected, with 725 children (240 females and 485 males) age 6 to 12 years (M = 8.63, SD = 1.72) split approximately evenly between those diagnosed with ADHD (n = 395) and age matched Non-ADHD/ Typical peers (n = 330). Data were collected in seven states from a total of 10 data collection sites. Institutional Review Board
Institutional review board
An institutional review board , also known as an independent ethics committee or ethical review board , is a committee that has been formally designated to approve, monitor, and review biomedical and behavioral research involving humans with the aim to protect the rights and welfare of the...
(IRB) approval for the overall project was established through Armstrong Atlantic State University
Armstrong Atlantic State University
Armstrong Atlantic State University, also referred to as Armstrong Atlantic, Armstrong, or simply AASU, is a four-year public university part of the University System of Georgia. It is located on a campus in suburban Savannah, Georgia, United States...
in Savannah, Georgia. All research sites included specialty ADHD assessment centers, each with independent IRB oversight, in Illinois, Georgia, Idaho, New Jersey, Tennessee, California, and Florida. Pedigo, Pedigo & Scott (2008).
Screening for possible comorbid conditions
The Computer Administered Diagnostic Interview (CADI) is used for comorbid screening, to assist clinicians with the collection and consolidation of pertinent patient information. The clinical protocol consists of 113 questions covering the major domains of co-occurring disorders. These areas include a medical and developmental history, emotional/social functioning, depression and anxiety symptoms, behavioral issues, school history, and attention/hyperactivity symptoms. This information is necessary to help structure an individual assessment process and to support recommendations that might be generated. The information is reviewed, with the parent or guardian, for cross validation of any concerns presented.Screening for inattention and hyperactivity
The Swanson, Nolan, and Pelham—IV (SNAP-IV) rating scale forms are included for parent / guardian and teachers to complete.The SNAP-IV rating scales offer categorical and dimensional input across the 18 core diagnostic items from the Diagnostic and Statistical Manual of Mental Disorders DSM-IV Fourth Edition-Revised. Each item is rated on a 4-point Likert scale
Likert scale
A Likert scale is a psychometric scale commonly involved in research that employs questionnaires. It is the most widely used approach to scaling responses in survey research, such that the term is often used interchangeably with rating scale, or more accurately the Likert-type scale, even though...
for severity. These behavioral criteria when used in the ascribed manner have produced reliable sensitivity and specificity in identifying ADHD cases relative to non-clinical reference groups. (Power, T. J., Andrews, T. J., Eiraldi, R. B., Doherty, B. J., Ikeda, M. J., DuPaul, G. J., & Landau, S.; 1998)
(Zolotor, A. J., & Mayer, J. ; 2004)
Objective measures
The Target Tests of Executive Functioning (TTEF) consist of three target subtests, Target Recognition, Target Sequencing and Target Tracking. They are designed to place distinctly different demands on several key areas of executive functioning that have been identified as important to ADHD assessment.(Biederman, J., Monuteaux, M. C., Doyle, A. E., Seidman, L. J., Wilens, T. E., Ferrero, F., Morgan, C. L., & Faraone, S. V.; 2004). The tests tap working memoryWorking memory
Working memory has been defined as the system which actively holds information in the mind to do verbal and nonverbal tasks such as reasoning and comprehension, and to make it available for further information processing...
, sequential memory and procedural memory
Procedural memory
Procedural memory is memory for how to do things. Procedural memory guides the processes we perform and most frequently resides below the level of conscious awareness. When needed, procedural memories are automatically retrieved and utilized for the execution of the integrated procedures involved...
functions, and help provide an objective assessment of a subject’s ability to employ various but not all executive processes such as planning, attending, organizing input, storing and retrieving information, modulating emotions and sustaining effort. These task demands have been consistently identified as areas of difficulty for children known to have ADHD.(Russell Barkley
Russell Barkley
Russell A. Barkley, Ph.D., is a Research Professor in the Department of Psychiatry at the State University of New York Upstate Medical University...
; 1997)
Demands basic to all three target subtests
- The child is pre-loaded to search and detect relevant information
- The child must inhibit irrelevant stimuli
- The child must use a metacognitive strategy forcing the use of internal dialogue
- The child must wait a short lag time before employing task demands
- The child must inhibit while formulating a plan of action
- The child must formulate, reconstitute and execute plans in the face of changing or novel stimuli
- The child must be sensitive and responsive to feedback
- The child must be able to do the above to discover that there are recurrent patterns presented in the task demands
- The child must employ motivational and emotional control in the service of ongoing activity
- The child must evaluate outcome against plans, intentions and feedback to direct future efforts accurately
Task specific demands for target recognition
Target Recognition takes approximately 8–10 minutes to complete, this subtest presents five large colored squares with smaller squares inside them. Below the squares are five small boxes labeled 1 to 5. The colored squares simultaneously blink on and off the screen at 1 ½ second intervals, in differing patterns for a total of 153 presentations. The child is taught a strategy to read from left to right and to count the number of large squares with small squares inside them of the same color and then to click on the corresponding number in the small box below labeled 1 to 5.Specific requirements for task completion include among others:
Attention to detail, avoiding distraction, maintenance of effort or persistence, holding information in mind through the use of metacognition
Metacognition
Metacognition is defined as "cognition about cognition", or "knowing about knowing." It can take many forms; it includes knowledge about when and how to use particular strategies for learning or for problem solving...
, feedback, and emotional regulation while developing a response to changes in novel stimuli.
Task specific demands for target sequencing
Target Sequencing takes approximately 8–10 minutes to complete, this subtest presents five large colored circles. A small colored square moves through each of them starting in the middle or at either of the end circles. The child is taught to attend only to circles when the square matches it in color and to say the name of the color to him or her self while at the same time disregarding the circles that have squares with a different color. Once the squares have moved through all five circles the child clicks on each of the circles that had matching colors in the same order that they stated to him/herself. First match first, second match second and last match last.Specific requirements for task completion include among others:
Attention to detail, avoiding distraction, maintenance of effort or persistence, holding information in mind through the use of metacognition, feedback, and emotional regulation during the initiation and follow through of a response to complex sequences while remaining sensitive to changes in novel stimuli.
Task specific demands for target tracking
Target Tracking takes approximately 8–10 minutes to complete, this subtest presents four colored shapes at the top and bottom of the screen. The computer creates one move at a time two and three step moves that the child must repeat/recreate in the same order seen. First move first, second move second and last move last.Specific requirements for task completion include among others:
Attention to detail, maintaining divided attention, holding information in mind, maintenance of effort or persistence and emotional regulation while completing complex two and three step instructions.
Scoring and reporting
The PADDS System and Summary Reports presents the incremental input of multiple forms of information that research has shown to be most reliable and valid for ADHD assessment. (Frazier & Youngstrom; 2006). The PADDS system uses a comparison of two well-defined reference groups namely ADHD and Non-ADHD. Each component is calculated in additive or subtractive manner for and against a diagnosis in consideration of the ADHD Base rateBase rate
In probability and statistics, base rate generally refers to the class probabilities unconditioned on featural evidence, frequently also known as prior probabilities...
. The inputs are displayed in a real time format via a computer generated Nomogram presenting an individual and an overall predictive index of likelihood ratios establishing evidence for or against a diagnosis. Results are likewise presented in a normalized, relative Standard score, T-score, Z-Score, and Percentile rank format for comparison to the non-clinical reference group
Reference group
A reference group is a concept referring to a group to which an individual or another group is compared.Sociologists call any group that individuals use as a standard for evaluating themselves and their own behavior a reference group....
.
The Nomographic display of the individual and cumulative inputs are evaluated stepwise via the calculation of likelihood ratios applied incrementally with a Fagan's Nomogram,(Fagan TJ ;1975) to produce an overall predictive index beginning with a calculated base rate, and combining the results of the other measures, in either an additive or subtractive manner, to provide a post-test probability. When these components are used in conjunction with clinical judgment they have proven to be highly effective for consideration of diagnosis, in highlighting and documenting a need for further evaluation or actions, and may allow the clinician to evaluate their own diagnostic practices and effectiveness over time.
Clinical use of the Pediatric Attention Disorders Diagnostic Screener (PADDS)
PADDS is used by: Child Psychiatrists, Child Psychologists, Neuro-psychologists, School Psychologists and PediatriciansThe PADDS is published by and available from Targeted Testing, Inc. and other major psychological test publishers.
See also
- Clinical neuropsychologyClinical neuropsychologyClinical neuropsychology is a sub-field of psychology concerned with the cognitive function of individuals with neurological and psychiatric disorders. Neuropsychological assessment examines cognitive function in the broadest sense, including the behavioural, emotional, social and functional status...
- Neuropsychological tests
- Clinical PsychologyClinical psychologyClinical psychology is an integration of science, theory and clinical knowledge for the purpose of understanding, preventing, and relieving psychologically-based distress or dysfunction and to promote subjective well-being and personal development...
- Executive functioning