The Palin Parent Rating Scales Sharon Millard Steve Davis Frances Cook 1
Overview Background to development of the parent rating scales The Delphi Study The exploratory factor analysis Normative Scores The Palin Parent Rating Scales (Palin PRS) 2
A measure that would take into account: The variability of stammering The impact of stammering on the child The impact of stammering on the parent - The broader aims of therapy Whether change is clinically significant Clients reports and evaluations of outcome 4
The Delphi Study Aim: obtain a group s opinion or judgment on a topic (Goodman 1987, p730) Principle: entails gathering information, opinions and ideas from a panel of experts using a specific sequence (Mead and Moseley, 2001) 5
Six Stages of a Delphi Study Selection of the expert panel Formulation of the question Generation of statements Reduction and categorisation Rating Analysis 6
The Questionnaire 26 items remained Series of 10 cm visual analogue scales Marked 0 and 10 at each end Use: Obtain score by measuring along the line Group scores into categories: stuttering severity; impact on child; impact on parent; parents knowledge and confidence 7
Limitations of scoring and interpretation No evidence to support the categorisation of the individual scales into the four areas Each scale receives the same weighting in the final score(s) No information about whether each contributes to the overall questionnaire 8
Aims To use exploratory factor analysis to establish the constructs underlying responses to the parent rating scales. To establish reliability of the parent rating scales To produce standardized scores for the factor constructs 9
Method Questionnaires completed at initial assessment 259 Parents (146 mothers, 113 fathers) Children aged 2;6 14;6 Male : female 3:1 10
Exploratory Factor Analysis Indicated that certain items were redundant final scale contains 19 items Revealed three components Impact on the child Severity of stammering and impact on the parents Parents knowledge and confidence in managing the stammering 11
Items loading on Factor 1 (impact on child) Does your child speak less because of the stammering? How frustrated is your child with his speech? How upset is your child by his stammering? How anxious is your child about his speech? How confident is your child in speaking situations? How happy is your child generally? How well can your child express how he feels? 12
Items loading on Factor 2 (severity and impact on parents) How worried are you about your child s stammering? How much is your child struggling? How anxious are you about your child s future because of the stammering? How often does your child stammer? How much of an impact does the stammering have on your family? How severe is your child s stammering Does your child have fluent times? 13
Items loading on Factor 3 (parent s knowledge and confidence) How confident are you in your knowledge of how to: Respond when your child is stammering encourage fluency in your child Deal with your child s concern / awareness of stammering Encourage confidence in your child Do you understand what influences your child s stammering? 14
Cronbach s alpha Reliability Measures the internal consistency of the scale Items should measure the same thing so should correlate with each other alpha increases when correlations between items increase Alpha of.7 and above considered as reliable 15
Reliability Alpha for complete scale -.882 For impact on child component -.865 For impact on parent/severity -.863 For parents knowledge and confidence -.838 Alpha for parents of younger children (n=166) -.862 Alpha for parents of older children (n=93) -.905 16
The resulting Palin PRS Consists of a series of 19 visual analogue rating scales There are 3 component factors: Impact on the child Severity of stammering and impact on the parents Parents knowledge and confidence in managing the stammering 17
Palin PRS How worried are you about your child s stammering? 0 10 as worried as not at all I possibly could be How worried is your child about his stammering? 0 10 as worried as not at all he possibly could be 18
Normalizing and scaling the factor scores First step is to produce weighted factor scores for each of the three factors: Each scale item differs in the amount it contributes to the factor Weighted factor scores take this into account Factor loading (amount scale contributes) is multiplied to the scale score to produce factor score Weighted factor scores then normalized to Z-scores based on mean and standard deviation and transformed to T-scores for ease of interpretation. 19
Normalizing and scaling the factor scores Normalised scores converted to stanine scores: Produces score from 1 to 9 Allows for easy interpretation of factor scores To assist in identification of areas that may be of concern To assist in monitoring change following intervention 20
Scale Categories for Factor 1 impact on the child Total Normed Score Stanine Score Percentile Category 25-31 1 1-4 Very Low 32-42 2-3 5-23 Low 43-58 4-6 24-77 Moderate 59-65 7-8 78-95 High 66+ 9 96-99 Very High 22
Scale Categories for Factor 2 severity and impact on parents Total Normed Score Stanine Score Percentile Category 28-33 1 1-4 Very Low 34-42 2-3 5-23 Low 43-57 4-6 24-77 Moderate 58-67 7-8 78-95 High 68+ 9 96-99 Very High 23
Scale Categories for Factor 3 parent s knowledge and confidence Total Normed Score Stanine Score Percentile Category 25-32 1 1-4 Very Low 33-42 2-3 5-23 Low 43-58 4-6 24-77 Moderate 59-65 7-8 78-95 High 66+ 9 96-99 Very High 24
Next steps Demonstrate use as an outcome measurement tool Programme for use Dissemination 25
Acknowledgements The Association for Research into Stammering in Childhood (ARSC) Islington PCT (Whittington Health)
Contact Details sharonmillard@nhs.net Stephen.davis@ucl.ac.uk Whittington Health 13-15 Pine Street London EC1R 0JH Tel: 020 3316 8100 27