Perjohan Lindfors
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Perjohan Lindfors has a total of 46 co-authors. Here are the top co-authors by number of shared publications:
- Hugo Hesser
Linköping University
5 shared publications - Brjánn Ljótsson
Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
4 shared publications - Erik Andersson
Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
4 shared publications - Erik Hedman
Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
4 shared publications Brjánn Ljótsson
Department of Clinical Neuroscience, Division of Psychology, Karolinska Institutet, Stockholm, Sweden
2 shared publications- Erland Axelsson
Division of Family Medicine and Primary Care, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Huddinge, Sweden
2 shared publications
Latest Publications
- Open Access
- 20 December 2023
- Published by MDPI AG in Gastrointestinal Disorders
- Vol. 6 (1) , 1-12
Gastrointestinal Group Education for Children and Adolescents with Functional Abdominal Pain Disorders—A Feasibility Study of a Brief Intervention
Functional abdominal pain disorders are common and disabling in children, but treatment options are limited. In a pilot study, we aimed to investigate if a brief group education program for pediatric patients with functional abdominal pain disorders and their parents is feasible and acceptable. Group education in adult irritable bowel syndrome has shown large treatment effects, but it has not been evaluated in children. The gastrointestinal (GI) group education, delivered in the clinic to 23 child–parent dyads, consisted of lectures by a pediatric gastroenterologist, a psychologist, and a dietician. Validated digital questionnaires were filled in by children and parents before and after the intervention. Most participants in the GI group education attended all sessions, and credibility in treatment was deemed high. Children’s self-reported knowledge of functional abdominal pain disorders increased, and improvements in gastrointestinal symptoms were reported at the end of this study. Our findings indicate that group education for children and adolescents with functional abdominal pain disorders, and their parents, is acceptable and feasible and may improve symptoms. A brief group education program may be of benefit in the management of pediatric functional abdominal pain disorders in several cases and when the family needs more knowledge than can be provided in primary care.
- 20 December 2023
- Published by MDPI AG in Gastrointestinal Disorders
- Vol. 6 (1) , 1-12
Open AccessGastrointestinal Group Education for Children and Adolescents with Functional Abdominal Pain Disorders—A Feasibility Study of a Brief Intervention
Functional abdominal pain disorders are common and disabling in children, but treatment options are limited. In a pilot study, we aimed to investigate if a brief group education program for pediatric patients with functional abdominal pain disorders and their parents is feasible and acceptable. Group education in adult irritable bowel syndrome has shown large treatment effects, but it has not been evaluated in children. The gastrointestinal (GI) group education, delivered in the clinic to 23 child–parent dyads, consisted of lectures by a pediatric gastroenterologist, a psychologist, and a dietician. Validated digital questionnaires were filled in by children and parents before and after the intervention. Most participants in the GI group education attended all sessions, and credibility in treatment was deemed high. Children’s self-reported knowledge of functional abdominal pain disorders increased, and improvements in gastrointestinal symptoms were reported at the end of this study. Our findings indicate that group education for children and adolescents with functional abdominal pain disorders, and their parents, is acceptable and feasible and may improve symptoms. A brief group education program may be of benefit in the management of pediatric functional abdominal pain disorders in several cases and when the family needs more knowledge than can be provided in primary care.
- Open Access
- 21 June 2023
- Published by Taylor & Francis in Cognitive Behaviour Therapy
- Vol. 52 (6) , 565-584
Psychological treatments for irritable bowel syndrome: a comprehensive systematic review and meta-analysis
A wide range of psychological treatments have been found to reduce the symptoms of irritable bowel syndrome (IBS) but their relative effects are unclear. In this systematic review and meta-analysis, we determined the effects of psychological treatments for IBS, including subtypes of cognitive behavior therapy, versus attention controls. We searched 11 databases (March 2022) for studies of psychological treatments for IBS, reported in journal articles, books, dissertations, and conference abstracts. The resulting database comprised 9 outcome domains from 118 studies published in 1983-2022. Using data from 62 studies and 6496 participants, we estimated the effect of treatment type on improvement in composite IBS severity using random-effects meta-regression. In comparison with the attention controls, there was a significant added effect of exposure therapy (g = 0.52, 95% CI = 0.17-0.88) and hypnotherapy (g = 0.36, 95% CI = 0.06-0.67) when controlling for the pre- to post-assessment duration. When additional potential confounders were included, exposure therapy but not hypnotherapy retained a significant added effect. Effects were also larger with a longer duration, individual treatment, questionnaire (non-diary) outcomes, and recruitment outside of routine care. Heterogeneity was substantial. Tentatively, exposure therapy appears to be a particularly promising treatment for IBS. More direct comparisons in randomized controlled trials are needed. OSF.io identifier: 5yh9a.
- 21 June 2023
- Published by Taylor & Francis in Cognitive Behaviour Therapy
- Vol. 52 (6) , 565-584
Open AccessPsychological treatments for irritable bowel syndrome: a comprehensive systematic review and meta-analysis
A wide range of psychological treatments have been found to reduce the symptoms of irritable bowel syndrome (IBS) but their relative effects are unclear. In this systematic review and meta-analysis, we determined the effects of psychological treatments for IBS, including subtypes of cognitive behavior therapy, versus attention controls. We searched 11 databases (March 2022) for studies of psychological treatments for IBS, reported in journal articles, books, dissertations, and conference abstracts. The resulting database comprised 9 outcome domains from 118 studies published in 1983-2022. Using data from 62 studies and 6496 participants, we estimated the effect of treatment type on improvement in composite IBS severity using random-effects meta-regression. In comparison with the attention controls, there was a significant added effect of exposure therapy (g = 0.52, 95% CI = 0.17-0.88) and hypnotherapy (g = 0.36, 95% CI = 0.06-0.67) when controlling for the pre- to post-assessment duration. When additional potential confounders were included, exposure therapy but not hypnotherapy retained a significant added effect. Effects were also larger with a longer duration, individual treatment, questionnaire (non-diary) outcomes, and recruitment outside of routine care. Heterogeneity was substantial. Tentatively, exposure therapy appears to be a particularly promising treatment for IBS. More direct comparisons in randomized controlled trials are needed. OSF.io identifier: 5yh9a.
- Open Access
- 6 May 2022
- Published by MDPI AG in Diagnostics
- Vol. 12 (5) , 1155
The Effectiveness and Tolerability of a Very Low-Volume Bowel Preparation for Colonoscopy Compared to Low and High-Volume Polyethylene Glycol-Solutions in the Real-Life Setting
Adequate bowel cleansing is essential for high-quality colonoscopy. Recently, a new very low-volume 1 litre (1L) polyethylene glycol (PEG) plus ascorbate solution (ASC) has been introduced. Our aims were to assess the effectiveness and tolerability of this product compared to low-volume 2L PEG-ASC and high-volume 4L PEG solutions, in a real-life setting. In six endoscopy units in Sweden, outpatients undergoing colonoscopy were either prescribed solutions according to local routines, or the very low-volume solution in split dose regimen. Bowel cleansing effectiveness and patient experience was assessed using the Boston Bowel preparation scale (BBPS) and a patient questionnaire. A total of 1098 patients (mean age 58 years, 52% women) were included. All subsegment and the total BBPS scores were significantly greater for 1L PEG-ASC in comparison to other solutions (p < 0.05 for 1L PEG-ASC and 4L PEG for transverse and left colon, otherwise p < 0.001). Nausea was more frequent with 1L PEG-ASC compared to 2L PEG-ASC (p < 0.001) and vomiting were more often reported compared to both other solutions (p < 0.01 and p < 0.05 for 2L PEG-ASC and 4L PEG, respectively). Smell, taste, and total experience was better for 1L PEG-ASC compared to 4L PEG (p < 0.001), and similar compared to the 2L PEG-ASC. In conclusion, 1L PEG-ASC leads to better bowel cleansing compared to 2L PEG-ASC or 4L PEG products, with similar or greater patient satisfaction.
- 6 May 2022
- Published by MDPI AG in Diagnostics
- Vol. 12 (5) , 1155
Open AccessThe Effectiveness and Tolerability of a Very Low-Volume Bowel Preparation for Colonoscopy Compared to Low and High-Volume Polyethylene Glycol-Solutions in the Real-Life Setting
Adequate bowel cleansing is essential for high-quality colonoscopy. Recently, a new very low-volume 1 litre (1L) polyethylene glycol (PEG) plus ascorbate solution (ASC) has been introduced. Our aims were to assess the effectiveness and tolerability of this product compared to low-volume 2L PEG-ASC and high-volume 4L PEG solutions, in a real-life setting. In six endoscopy units in Sweden, outpatients undergoing colonoscopy were either prescribed solutions according to local routines, or the very low-volume solution in split dose regimen. Bowel cleansing effectiveness and patient experience was assessed using the Boston Bowel preparation scale (BBPS) and a patient questionnaire. A total of 1098 patients (mean age 58 years, 52% women) were included. All subsegment and the total BBPS scores were significantly greater for 1L PEG-ASC in comparison to other solutions (p < 0.05 for 1L PEG-ASC and 4L PEG for transverse and left colon, otherwise p < 0.001). Nausea was more frequent with 1L PEG-ASC compared to 2L PEG-ASC (p < 0.001) and vomiting were more often reported compared to both other solutions (p < 0.01 and p < 0.05 for 2L PEG-ASC and 4L PEG, respectively). Smell, taste, and total experience was better for 1L PEG-ASC compared to 4L PEG (p < 0.001), and similar compared to the 2L PEG-ASC. In conclusion, 1L PEG-ASC leads to better bowel cleansing compared to 2L PEG-ASC or 4L PEG products, with similar or greater patient satisfaction.
- Open Access
- 13 July 2021
- Published by Springer Nature in BMC Gastroenterology
- Vol. 21 (1) , 1-13
Return on investment of internet delivered exposure therapy for irritable bowel syndrome: a randomized controlled trial
Background: Irritable bowel syndrome (IBS) is a debilitating and costly disorder. Cognitive behavior therapy (CBT) is effective in the treatment of IBS, both when delivered over the internet and in face-to-face settings. CBT consists of different components and little is known about their relative importance. We have in an earlier study showed that inclusion of exposure in the CBT for IBS makes it even more effective. In the present study we wanted to evaluate the economic effects for society of inclusion vs exclusion of exposure in an internet delivered CBT for IBS. Methods: We used data from a previous study with 309 participants with IBS. Participants were randomized to internet delivered CBT with (ICBT) or without exposure (ICBT-WE). We compared direct and indirect costs at baseline, after treatment, and 6 months after treatment (primary endpoint; 6MFU). Data was also collected on symptom severity and time spent by therapists and participants. The relative Incremental Cost Effectiveness Ratio (ICER) was calculated for the two treatment conditions and the return on investment (ROI). Results: Results showed that ICBT cost $213.5 (20%) more than ICBT-WE per participant. However, ICBT was associated with larger reductions regarding both costs and symptoms than ICBT-WE at 6MFU. The ICER was − 301.69, meaning that for every point improvement on the Gastrointestinal Symptom Rating Scale—IBS version in ICBT, societal costs would be reduced with approximately $300. At a willingness to pay for a case of clinically significant improvement in IBS symptoms of $0, there was an 84% probability of cost-effectiveness. ROI analysis showed that for every $1 invested in ICBT rather than ICBT-WE, the return would be $5.64 six months after treatment. Analyses of post-treatment data showed a similar pattern although cost-savings were smaller. Conclusions: Including exposure in Cognitive Behavior Treatment for IBS is more cost-effective from a societal perspective than not including it, even though it may demand more therapist and patient time in the short term. Trial registration: This study is reported in accordance with the CONSORT statement for non-pharmacological trials [1]. Clinicaltrials.gov registration ID: NCT01529567 (14/02/2013).
- 13 July 2021
- Published by Springer Nature in BMC Gastroenterology
- Vol. 21 (1) , 1-13
Open AccessReturn on investment of internet delivered exposure therapy for irritable bowel syndrome: a randomized controlled trial
Background: Irritable bowel syndrome (IBS) is a debilitating and costly disorder. Cognitive behavior therapy (CBT) is effective in the treatment of IBS, both when delivered over the internet and in face-to-face settings. CBT consists of different components and little is known about their relative importance. We have in an earlier study showed that inclusion of exposure in the CBT for IBS makes it even more effective. In the present study we wanted to evaluate the economic effects for society of inclusion vs exclusion of exposure in an internet delivered CBT for IBS. Methods: We used data from a previous study with 309 participants with IBS. Participants were randomized to internet delivered CBT with (ICBT) or without exposure (ICBT-WE). We compared direct and indirect costs at baseline, after treatment, and 6 months after treatment (primary endpoint; 6MFU). Data was also collected on symptom severity and time spent by therapists and participants. The relative Incremental Cost Effectiveness Ratio (ICER) was calculated for the two treatment conditions and the return on investment (ROI). Results: Results showed that ICBT cost $213.5 (20%) more than ICBT-WE per participant. However, ICBT was associated with larger reductions regarding both costs and symptoms than ICBT-WE at 6MFU. The ICER was − 301.69, meaning that for every point improvement on the Gastrointestinal Symptom Rating Scale—IBS version in ICBT, societal costs would be reduced with approximately $300. At a willingness to pay for a case of clinically significant improvement in IBS symptoms of $0, there was an 84% probability of cost-effectiveness. ROI analysis showed that for every $1 invested in ICBT rather than ICBT-WE, the return would be $5.64 six months after treatment. Analyses of post-treatment data showed a similar pattern although cost-savings were smaller. Conclusions: Including exposure in Cognitive Behavior Treatment for IBS is more cost-effective from a societal perspective than not including it, even though it may demand more therapist and patient time in the short term. Trial registration: This study is reported in accordance with the CONSORT statement for non-pharmacological trials [1]. Clinicaltrials.gov registration ID: NCT01529567 (14/02/2013).
- Open Access
- 1 June 2021
- Published by Elsevier in Behaviour Research and Therapy
- Vol. 141, 103862
Behavioral avoidance moderates the effect of exposure therapy for irritable bowel syndrome: A secondary analysis of results from a randomized component trial
- 1 June 2021
- Published by Elsevier in Behaviour Research and Therapy
- Vol. 141, 103862
Open AccessBehavioral avoidance moderates the effect of exposure therapy for irritable bowel syndrome: A secondary analysis of results from a randomized component trial
- 1 April 2021
- Published by Elsevier in Clinical Gastroenterology and Hepatology
- Vol. 19 (4) , 743-751.e1
Online Education Is Non-Inferior to Group Education for Irritable Bowel Syndrome: A Randomized Trial and Patient Preference Trial
- 1 April 2021
- Published by Elsevier in Clinical Gastroenterology and Hepatology
- Vol. 19 (4) , 743-751.e1
Online Education Is Non-Inferior to Group Education for Irritable Bowel Syndrome: A Randomized Trial and Patient Preference Trial
- 1 April 2014
- Published by Elsevier in Behaviour Research and Therapy
- Vol. 55, 27-39
Provoking symptoms to relieve symptoms: A randomized controlled dismantling study of exposure therapy in irritable bowel syndrome
- 1 April 2014
- Published by Elsevier in Behaviour Research and Therapy
- Vol. 55, 27-39
Provoking symptoms to relieve symptoms: A randomized controlled dismantling study of exposure therapy in irritable bowel syndrome
- Open Access
- 19 November 2013
- Published by Springer Nature in BMC Gastroenterology
- Vol. 13 (1) , 160
Prediction of symptomatic improvement after exposure-based treatment for irritable bowel syndrome
Several studies show that psychological treatments relieve symptoms for patients suffering from irritable bowel syndrome (IBS). However, there are no consistent findings that show what patient characteristics make a psychological treatment more or less likely to result in improvement. We have previously conducted a study of a newly developed internet-delivered cognitive behavioral therapy (ICBT) that emphasized exposure to IBS symptoms and IBS-related situations and reduced symptom-related avoidance. The study showed that the treatment led to improvement in IBS symptoms compared to a waiting list and that treatment gains were maintained over a 15–18 month follow-up period. The aim of the present study was to investigate several possible predictors of short- and long-term treatment outcome in terms of symptom improvement, based on data collected in the previously conducted treatment trial.
- 19 November 2013
- Published by Springer Nature in BMC Gastroenterology
- Vol. 13 (1) , 160
Open AccessPrediction of symptomatic improvement after exposure-based treatment for irritable bowel syndrome
Several studies show that psychological treatments relieve symptoms for patients suffering from irritable bowel syndrome (IBS). However, there are no consistent findings that show what patient characteristics make a psychological treatment more or less likely to result in improvement. We have previously conducted a study of a newly developed internet-delivered cognitive behavioral therapy (ICBT) that emphasized exposure to IBS symptoms and IBS-related situations and reduced symptom-related avoidance. The study showed that the treatment led to improvement in IBS symptoms compared to a waiting list and that treatment gains were maintained over a 15–18 month follow-up period. The aim of the present study was to investigate several possible predictors of short- and long-term treatment outcome in terms of symptom improvement, based on data collected in the previously conducted treatment trial.