META-ANALYSIS OF APPRAISALS IN PTSD i Doctoral Thesis The Relationship between ...

335 Pages·2017·3.76 MB·English

by  Gina Gomez

Running head: META-ANALYSIS OF APPRAISALS IN PTSD

Doctoral Thesis

The Relationship between Maladaptive Appraisals and Posttraumatic Stress
Disorder: A Meta-Analysis

Georgina Gómez de la Cuesta

Submission date: 7th March 2017
Word count: 38799

Doctoral Programme in Clinical Psychology
University of East Anglia

© This copy of the thesis has been supplied on condition that anyone who consults it
is understood to recognise that its copyright rests with the author and that use of any
information derived there from must be in accordance with current UK Copyright
Law. In addition, any quotation or extract must include full attribution.
i
META-ANALYSIS OF APPRAISALS IN PTSD
Abstract
Background
Cognitive models of posttraumatic stress disorder (PTSD) suggest maladaptive
appraisals about the self, the world and one’s symptoms in the aftermath of trauma
play a causal role in the aetiology of PTSD (e.g. Ehlers & Clark, 2000). The current
meta-analysis aims to provide a thorough, quantitative examination of the
relationship between maladaptive appraisals and PTSD.
Methods
A systematic search of relevant databases was conducted. Effect sizes and study
characteristics were extracted from eligible studies and 20 per cent double coded for
inter-rater reliability. A series of random-effects meta-analyses using Hedge’s (1985)
method were performed. Subgroup analyses, sensitivity analyses and assessment of
publication bias were examined.
Results
Results showed a large effect size in the overall meta-analysis (r = 0.53, 95% CI =
0.51-0.56, k = 147). In studies using only the Posttraumatic Cognitions Inventory or
Child Posttraumatic Cognitions Inventory, the effect size remained large (r = 0.56;
95% CI = 0.53-0.59, k = 104). In adults, maladaptive appraisals about the self had a
very large effect size (r = 0.61, 95% CI = 0.57-0.64, k = 66), maladaptive appraisals
about the world had a medium effect size (r = 0.45, 95% CI = 0.41-0.49, k = 62)
and self-blame appraisals had a small-medium effect size (r = 0.28, 95% CI = 0.24-
0.33, k = 59). In child/adolescent studies, there was no difference in effect size
between appraisals of being a fragile person in a scary world or appraisals of
permanent change (r = 0.53, 95% CI = 0.43-0.62 and r = 0.59, 95% CI = 0.48-
0.67, respectively, k = 12). The effect size of the relationship between maladaptive
ii
META-ANALYSIS OF APPRAISALS IN PTSD
appraisals and PTSD symptoms reduced at 12 months following trauma (2-4 months:
r = 0.53, k = 9; 6 months: r = 0.53, k = 13; 12 months: r = 0.32, k = 3). All results
were robust to sensitivity analyses and there was no evidence of publication bias.
Discussion
Findings underline the importance of maladaptive appraisals in the aetiology of
PTSD and highlight the role of self appraisals in adults. Avenues for future research
include more studies in child, multiple trauma and military populations and longer
term follow up studies.
Keywords: Posttraumatic stress disorder, PTSD, appraisals, posttraumatic
cognitions, negative beliefs, meta-analysis
iii
META-ANALYSIS OF APPRAISALS IN PTSD
List of Contents
Abstract…………………………………………………………………………….....ii
Contents....…………………………………………………………………………...iii
List of Tables …..........................................................................................................vi
List of Figures..............................................................................................................vii
Acknowledgements…………………………………………………………………...x
Introduction .................................................................................................................. 1
1.1 Chapter Summary ....................................................................................................... 1
1.2 Posttraumatic Stress Disorder ................................................................................... 1
1.3 Appraisals and Emotion ........................................................................................... 11
1.4 Psychological models of PTSD ............................................................................... 19
1.5 Maladaptive Appraisals and PTSD ......................................................................... 31
1.6 Psychological Treatments for PTSD ...................................................................... 45
1.7 Rationale for the Current Study .............................................................................. 48
1.8 Aims ............................................................................................................................ 52
1.9 Research Questions ................................................................................................... 52
Method ....................................................................................................................... 53
2.1 Introduction ................................................................................................................ 53
2.2 Registration of Research .......................................................................................... 53
2.3 Search Strategy .......................................................................................................... 53
2.4 Eligibility Screening ................................................................................................. 56
2.5 Data Extraction .......................................................................................................... 58
2.6 Calculating effect sizes ............................................................................................. 60
2.7 Quality Assessment Framework ............................................................................. 65
2.8 Data Synthesis ........................................................................................................... 69
Results ........................................................................................................................ 77
3.1 Chapter Outline ......................................................................................................... 77
3.2 Search Results ........................................................................................................... 77
3.3 Study Characteristics ................................................................................................ 79
3.4 Meta-Analysis of Overall Effect Size .................................................................... 99
iv
META-ANALYSIS OF APPRAISALS IN PTSD
3.5 Meta-Analysis of Overall Effect Size Using PTCI/CPTCI only ...................... 107
3.6 Meta-Analysis of Subtypes of Maladaptive Appraisal ...................................... 112
3.7 Meta-Analysis of Effect Size Change over Time ............................................... 142
Discussion ................................................................................................................ 154
4.1 Summary of Results ................................................................................................ 154
4.2 Strengths of the current study………………………………………………..156
4.3 Limitations of the current study……………………………………………..............................158
4.4 Comparison to Existing Risk Factor Meta-Analyses ......................................... 162
4.5 Theoretical Implications ......................................................................................... 165
4.6 Clinical Implications ............................................................................................... 174
4.7 Suggestions for Future Research........................................................................... 177
4.8 Conclusion ............................................................................................................... 180
References………………………………………………………………………....183
Appendix A. Prospero entry……………………………………………………….249
Appendix B. Example search output………………………………………………261
Appendix C. Data extraction form cross sectional studies………………………...262
Appendix D. Data extraction form, prospective studies…………………………..270
Appendix E. Data extraction form, between groups studies………………………281
Appendix F. Full text studies reviewed and reasons for exclusion………………..296
Appendix G. Contribution of each study to meta-analysis of overall effect size….304
Appendix H. Table of outliers excluded from overall effect size analysis………...308
Appendix I. Contribution of each study to meta-analysis of PTCI/CPTCI………..310
Appendix J. Table of outliers excluded from PTCI/CPTCI meta-analysis………..313
Appendix K. Contribution of each study to overall effect size for PTCI-Self ……314
Appendix L. Table of outliers excluded from PTCI-Self analysis………………...316
Appendix M. Contribution of each study to overall effect size for PTCI-World….317
Appendix N. Table of outliers from appraisals about the world…………………..319
Appendix O. Contribution of each study to overall effect size for Self-blame……320
Appendix P. Table of outliers for self-blame appraisals…………………………..322
Appendix Q. Items from the Posttraumatic Cognitions Inventory………………...323
Appendix R. Items from the Child Posttraumatic Cognitions Inventory………….325
v
META-ANALYSIS OF APPRAISALS IN PTSD

List of Tables

Table 1.1 Self-Report Questionnaires of Maladaptive Appraisals…………………..………40
Table 2.1. Search Terms……………………………………………………………………..54
Table 2.2. Quality Assessment Framework Questions…………………………………........68
Table 3.1. Study characteristics: sample, trauma characteristics and study quality…………84
Table 3.2. Study characteristics: study design, recruitment and assessment times………….91
Table 3.3. Inter-Rater Reliability of Study Quality Ratings…………………………………99
Table 3.4. Table of Results from Overall and Subgroup Meta-Analyses………………..…104
Table 3.5. Table of Subgroup Analysis and Sensitivity Analysis for PTCI and CPTCI…...110
Table 3.6. Table of Subgroup Analysis and Sensitivity Analysis Results for PTCI Self…..116
Table 3.7. Table of Subgroup Analysis and Sensitivity Analysis Results for PTCI World...120
Table 3.8. Table of Subgroup Analysis and Sensitivity Analysis for PTCI Self-Blame…...126
Table 3.9. Table of Subgroup Analysis and Sensitivity Analysis CPTCI FP/SW…..……..132
Table 3.10. Table of Subgroup Analysis and Sensitivity Analysis CPTCI PC………….…139
vi
META-ANALYSIS OF APPRAISALS IN PTSD
List of Figures
Figure 1.1. The Cognitive Model of PTSD (Ehlers & Clark, 2000)………………………...27
Figure 3.1. PRISMA diagram outlining study selection process……………………………79
Figure 3.2 Stem-and-leaf plot of Pearson’s correlations for pooled effect size for overall
meta-analysis ……………………………………………………………………………...100
Figure 3.3. Forest plot to show the overall effect size and subgroup analyses relating to study
methodology…………………………………………………………………………….…101
Figure 3.4. Forest plot to show the overall effect size and subgroup analyses exploring the
influence of trauma characteristics………………………………………………………..102
Figure 3.5. Funnel plot of standard error by Fisher’s Z for overall effect size showing the
symmetry of the data in relation to publication bias………………….…………………...106
Figure 3.6. Stem-and-leaf plot of Pearson’s correlations for pooled effect size for
PTCI/CPTCI studies only………………………………….………………………………107
Figure 3.7. Forest plot showing subgroup analyses related to methodological and study
characteristics for meta-analysis of PTCI/CPTCI studies only…………………………….108
Figure 3.8. Forest plot showing subgroup analyses related to trauma characteristics for meta-
analysis of PTCI/CPTCI studies only………………………………………………………109
Figure 3.9. Funnel plot of effect sizes exploring publication bias for meta-analysis of
appraisals measured using PTCI and CPTCI……………………………………………….112
Figure 3.10. Stem-and-leaf plot of effect sizes for appraisals of the self in adults………....113
Figure 3.11. Forest plot for appraisals of the self, subgroup analyses and sensitivity
analyses……………………………………………………………………………………..114
Figure 3.12. Funnel plot of effect sizes for appraisals about the self, exploring publication
bias………………………………………………………………………………………….117
Figure 3.13. Stem-and-Leaf plot showing effect sizes for appraisals about the world……..118
vii
META-ANALYSIS OF APPRAISALS IN PTSD
Figure 3.14. Forest plot showing effect size for adult appraisals about the world, subgroup
analyses and sensitivity analyses……………………………………………………………121
Figure 3.15. Funnel plot showing distribution of effect size by standard error for appraisals
about the world in adults……………………………………………………………………123
Figure 3.16. Stem-and-leaf plot showing effect sizes extracted for self-blame appraisals…124
Figure 3.17. Forest plot showing pooled effect size, subgroup and sensitivity analysis for self-
blame appraisals…………………………………………………………………………….125
Figure 3.18. Funnel plot to explore publication bias for self-blame appraisal data………..128
Figure 3.19. Forest plot to show meta-analysis results of CPTCI subscale “fragile person in a
scary world” in children…………………………………………………………………….130
Figure 3.20. Forest plot showing overall effect size, subgroup and sensitivity analyses for
fragile person/scary world appraisals in children and adolescents…………………………132
Figure 3.21. Funnel plot to explore publication bias for child/adolescent appraisals of being a
fragile person in a scary world……………………………….……………………………..134
Figure 3.22. Forest plot showing random effects meta-analysis results for children’s
appraisals of permanent change and PTSD symptoms……………………………………..136
Figure 3.23. Forest plot showing subgroup and sensitivity analyses for children’s appraisals
about permanent change…………………………………………………………………….138
Figure 3.24. Funnel plot to explore publication bias for child/adolescent appraisals of
permanent change…………………………………………………………………………..140
Figure 3.25. Forest plot showing effect sizes across different subtypes of maladaptive
appraisal…………………………………………………………………………………….142
Figure 3.26. Forest plot showing effect size of the relationship between appraisals within 1
month of trauma and PTSD symptoms 2-4 months following trauma………………..……143
viii
META-ANALYSIS OF APPRAISALS IN PTSD
Figure 3.27. Funnel plot to explore publication bias for effect size 2-4 months following
trauma……………………………………………………………………………………….144
Figure 3.28. Forest plot showing effect size of the relationship between appraisals within 1
month of trauma and PTSD symptoms 6 months following trauma…………….…………146
Figure 3.29. Funnel plot to explore publication bias for effect size 6 months following
trauma……………………………………………………………………………………….147
Figure 3.30. Forest plot showing effect size of the relationship between appraisals within 1
month of trauma and PTSD symptoms 12 months following trauma………………………149
Figure 3.31. Forest plot showing effect size at 2-4 months, 6 months and 12 months since
trauma……………………………………………………………………………………….151
Figure 3.32. Subgroup analysis showing effect size of the relationship between maladaptive
appraisals and PTSD symptoms over time…………………………………………………153

ix
META-ANALYSIS OF APPRAISALS IN PTSD
Acknowledgements
Firstly, I would like to thank Dr. Richard Meiser-Stedman for his excellent
supervision during this piece of work. Thank you for the ideas, knowledge and
expertise and for going beyond the call of duty with such kindness, thoughtfulness
and energy. I am so grateful that you suggested doing a meta-analysis and I have
learned so much from our work together. I could not have asked for a better
supervisor.
I would like to express my gratitude to Dr. Suzanne Schweizer and Dr. Julia
Diehle for their assistance with data extraction and inter-rater reliability. Thank you
to Dr. Judith Young for her thoughtful comments on the first draft and to Dr. David
Peck for his statistical support.
Finally, I would like to express my heartfelt thanks and love to my family and
friends. It is not only me doing this doctorate, it is a whole system, and without the
incredible support from my family none of this work would have been possible. To
Ramón, who has put up with so much over the past 5 years, thank you for always
being on my side and for holding the fort whilst I have scribbled away. Mum and
Dad, thank you for your unending support and encouragement and for all the extra
childcare duties. Emma, our fabulous nanny, thank you for all the additional hours
and for being an irreplaceable extra member of our family. To all my friends who
have kept me sane and encouraged me, thank you- I will be a better and more
available friend soon! And finally, to my fabulous, funny, intelligent children,
Miguel and Silvia: Thank you for being your perfect selves and for never letting me
forget what the important things in life are. I am doing this for you.

x