Paul Ritvo | York University (original) (raw)
Papers by Paul Ritvo
JMIR Research Protocols, May 12, 2023
Background: Exposures to "traumatic" events are widespread and can cause posttraumatic stress dis... more Background: Exposures to "traumatic" events are widespread and can cause posttraumatic stress disorder (PTSD). Cognitive behavioral therapy and eye movement desensitization and reprocessing (EMDR) are frequently used and validated behavioral PTSD treatments. Despite demonstrated effectiveness, highly upsetting memory reactions can be evoked, resulting in extensive distress and, sometimes, treatment dropout. In recent years, multiple treatment approaches have aimed at reducing such upsetting memory reactions to traumatic memories while therapeutic progress proceeds. One of these methods, the flash technique (FT), a modification of standard EMDR (S-EMDR), appears effective in distressing memory reduction. This study will examine FT-EMDR and S-EMDR efficacies when both methods are delivered via web-based video. Objective: This study aims to assess the relative efficacy of (web-based) FT-EMDR versus S-EMDR in reducing the PTSD symptoms, anxieties, and depression associated with traumatic memories at postintervention and 1-month follow-up. Methods: This double-blinded, web-based, 2-arm randomized controlled trial will employ self-report outcomes. A total of 90 participants will be identified from the web-based CloudResearch platform and randomly allocated to the experimental or comparison group. Inclusion criteria are as follows: (1) approved for engagement by the CloudResearch platform; (2) 25-60 years of age; (3) residing in Canada or the United States; (4) a recalled disturbing memory of an event >2 years ago that has not repeated and was moderately or more upsetting during occurrence; (5) memory moderately or more upsetting at baseline and not linked to an earlier memory that is equally or more than equally disturbing. Exclusion criteria are bipolar disorder, borderline personality disorder, obsessive-compulsive disorder, schizophrenia, substance abuse or addiction in the past 3 months, suicidal ideation, and suicide attempt in the past 6 months. Interventions include guided video instruction of full FT or guided video of EMDR.
BACKGROUND Exposures to “traumatic” events are widespread and can cause posttraumatic stress diso... more BACKGROUND Exposures to “traumatic” events are widespread and can cause posttraumatic stress disorder (PTSD). Cognitive behavioral therapy and eye movement desensitization and reprocessing (EMDR) are frequently used and validated behavioral PTSD treatments. Despite demonstrated effectiveness, highly upsetting memory reactions can be evoked, resulting in extensive distress and, sometimes, treatment dropout. In recent years, multiple treatment approaches have aimed at reducing such upsetting memory reactions to traumatic memories while therapeutic progress proceeds. One of these methods, the flash technique (FT), a modification of standard EMDR (S-EMDR), appears effective in distressing memory reduction. This study will examine FT-EMDR and S-EMDR efficacies when both methods are delivered via web-based video. OBJECTIVE This study aims to assess the relative efficacy of (web-based) FT-EMDR versus S-EMDR in reducing the PTSD symptoms, anxieties, and depression associated with traumatic memories at postintervention and 1-month follow-up. METHODS This double-blinded, web-based, 2-arm randomized controlled trial will employ self-report outcomes. A total of 90 participants will be identified from the web-based CloudResearch platform and randomly allocated to the experimental or comparison group. Inclusion criteria are as follows: (1) approved for engagement by the CloudResearch platform; (2) 25-60 years of age; (3) residing in Canada or the United States; (4) a recalled disturbing memory of an event >2 years ago that has not repeated and was moderately or more upsetting during occurrence; (5) memory moderately or more upsetting at baseline and not linked to an earlier memory that is equally or more than equally disturbing. Exclusion criteria are bipolar disorder, borderline personality disorder, obsessive-compulsive disorder, schizophrenia, substance abuse or addiction in the past 3 months, suicidal ideation, and suicide attempt in the past 6 months. Interventions include guided video instruction of full FT or guided video of EMDR. Outcome measures are as follows: Primary outcome is PTSD symptoms that are measured by the PTSD Checklist for DSM-5 (Diagnostic and Statistical Manual of Mental Disorders-5) at 1-month follow-up. Secondary outcomes are State Anxiety subscale of State-Trait Anxiety Inventory at baseline, postintervention, and 1-month follow-up; Trait Anxiety subscale of State-Trait Anxiety Inventory; depression (Patient Health Questionnaire-9); and Positive and Negative Affect Schedule measured at 1-month follow-up. RESULTS If, at 1-month follow-up, the web-based FT-EMDR intervention is more effective in reducing PTSD symptoms (as measured by the PTSD Checklist for DSM-5) than EMDR, it may help reduce traumatic memory distress in multiple contexts. CONCLUSIONS This randomized controlled trial will advance current understandings of PTSD symptoms and interventions that target traumatic memory–related distress. CLINICALTRIAL ClinicalTrials.gov NCT05262127; https://clinicaltrials.gov/ct2/show/NCT05262127
Archives of Physical Medicine and Rehabilitation, Aug 1, 1994
TJ. Functional competence of communitydwelling persons with multiple sclerosis using the assessme... more TJ. Functional competence of communitydwelling persons with multiple sclerosis using the assessment of motor and process skills. Arch Phys Med Rebabil 1994:75:843-51. l The Assessment of Motor and Process Skills (AMPS) is an observational measure of functional competence in instrumental activities of daily living (IADL) that was designed to overcome the limitations of self reports and proxy reports. The AMPS allows simultaneous evaluation of the underlying motor and process (organizational/ adaptive) skills necessary for competent task performance. We examined the IADL performance of 22 communitydwelling patients with mild to moderate MS in comparison to nondisabled subjects matched for age and gender. Functional competence of the MS subjects, as measured by the AMPS, was poorer than that of the control group. Many MS subjects who would not have been expected to have IADL difficulties on the basis of ratings of neurologic impairment were impaired in their IADL performance. For some patients, IADL impairment reflected deficits in their motor and process skills, whereas for others, process skill impairments alone were responsible for deficient task performance.
BMJ Open, Nov 1, 2022
Objectives The study objective was to understand the barriers and facilitators to healthy active ... more Objectives The study objective was to understand the barriers and facilitators to healthy active living in South Asian families living in Canada. Design Semi-structured interviews of 30-60-minute duration with South Asian women with young families, and analysed using a thematic analytical approach. Setting Community-dwelling South Asian women interviewed in the home environment or by phone. Participants Fifteen married South Asian women (mean age=34.2 years) living in the Peel region of Ontario, Canada, with at least 1 child under the age of 5 years. The majority of women had immigrated to Canada (13/15), during a 5-10-year interval preceding interviews. Results 57 different codes were derived from 18 interview hours, and further evaluated through member checking. The top three barriers to healthy eating were: (1) not having enough time for healthy food preparation, (2) lack of knowledge about what is healthy eating and (3) viewing healthy eating as a matter of engaging in time limited dieting. These barriers were addressed with: (1) knowledge and awareness of healthy eating, (2) clear goal setting, (3) access to fresh vegetables and fruits and (4) better arrangements and more time for food preparation. The top five barriers to physical activity were: (1) not enough time and energy, (2) competing priorities, (3) lack of childcare, (4) lack of family-engaging exercise and (5) limited access to interesting exercise programming. These barriers were addressed by: (1) experiencing exercise as enjoyable and stress releasing, (2) commitments to walking exercise, (3) use of an electronic exercise-tracking device, (4) offspring exercise supported by spouse and family and (5) success stories about exercise from others. Conclusions Barriers to healthy active living in South Asian women with young families can be addressed with facilitators that stimulate clear goal setting and healthy food preparation skills, and exercise formats that engage mothers and offspring, with or without exercise tracking.
Post-traumatic stress disorder is a major public health concern with a lifetime prevalence rate o... more Post-traumatic stress disorder is a major public health concern with a lifetime prevalence rate of 6.1-9.2% in North America. PTSD is known to alter the autonomic nervous system leading to chronic sympathetic arousal including heightened anxiety and hypervigilance. Pupillometry offers a quick and accessible measure of autonomic nervous system imbalances characteristic of PTSD. This study investigates the utility of pupillometry as a biomarker to detect PTSD in a sample of 39 adults with (n = 22) and without (n = 17) PTSD. Participants viewed a 25-minute computer protocol consisting of 5-minute rest phase, 10-minute negative emotionally valent images, and 10-minute guided meditation. We relied on a time-frequency analysis to represent the pupillary responses of two different groups (PTSD-affected individuals and healthy-control subjects). These data were then employed with a CNN network to learn a prediction model. Individuals with PTSD demonstrated increased pupil dilation across the entire protocol. The final outcome revealed an accuracy of 81.09% which indicates the feasibility of using this approach to detecting participants with PTSD in an automated way. Findings from this research have important implications for clinical mental health assessment, diagnostics and treatment.
Canadian Journal of Cardiology, Oct 1, 2019
Canadian Journal of Cardiology, Oct 1, 2019
![Research paper thumbnail of A Feasibility Pilot Study to Assess the Efficacy of NavX Guided Detection of Pulmonary Vein Electrograms during Atrial Fibrillation Ablation [NavX Guided Detection of Pulmonary Vein Electrograms]](https://attachments.academia-assets.com/117820910/thumbnails/1.jpg)
](International journal of clinical cardiology, Sep 30, 2017
Canadian Journal of Neurological Sciences, Feb 1, 1994
JMIR mental health, Dec 2, 2020
Journal of the American College of Cardiology, Apr 1, 2016
Background: Atrial Fibrillation (AF) ablation is a common intervention for patient suffering from... more Background: Atrial Fibrillation (AF) ablation is a common intervention for patient suffering from drug refractory symptomatic AF. Unfortunately a number of patients require repeat procedures to ensure success. Objective software-based demarcation of ablation lesions based on catheter stability may improve procedural success. The purpose of this study was to test whether this strategy improves outcomes of Pulmonary Vein Antral Isolation (PVAI) compared to subjective lesion demarcation by the operator. Methods: Patients were divided into 2 groups, those who had the procedure done using VISITAG™ Technology (Group A), and age-gender matched control patients ablated during a 12 month period prior to the introduction of this technology (Group B). Baseline, procedure and outcome data were obtained for 97 patients ([40 in group A] and [57 in group B]). Mean age for Groups A and B were 63.3±8.51 and 60±13.1 (p=0.01) respectively. In all patients PVAI was guided by intracardiac ECHO and a circular mapping catheter using CARTO3 3D mapping system, and a Thermocool ablation catheter. In Group A lesions were demarcated automatically at 3mm/7sec VISITAG setting, while in Group B Lesions were demarcated by the operator. ECG was performed at 1, 3, 6, and 12 months. Recurrences ≤ 3 months were considered Early (ER), while recurrences after 3 months were considered Late (LR). Using survival analysis, rates of ER and LR stratified by AF type [Paroxysmal AF (PAF) vs. Non-PAF (NPAF)] were compared. Only outcomes during the first 12 months of follow-up were compared. Results: The rates of ER and LR were lower in patients in Group A vs. Group B (30.0% vs. 52.6%, p=0.05 and 20.0% vs. 42.1%, p=0.05 respectively). Furthermore, patients with PAF had dramatically lower ER rate in Group A vs. Group B (16.7% vs. 48.4%, p=0.04), while NPAF patients had a significant improvement in LR (18.6% vs. 48.0%, p=0.003). Procedure, and fluoroscopy time differences were not significant. Conclusions: Objective demarcation of lesions based on catheter stability during PVAI procedures results in a significant improvement in AF recurrence rates during 12 months of follow-up. Technologies enabling this strategy warrant further clinical evaluation.
Canadian Family Physician, Feb 1, 2009
Colorectal cancer (CRC) is the third most common cancer in the United States. A reduction in cumu... more Colorectal cancer (CRC) is the third most common cancer in the United States. A reduction in cumulative mortality occurs when patients are routinely screened by fecal occult blood tests (FOBT) and early lesions are removed. These point-of-care tests detect minute amounts of blood released from precancerous and cancerous colon lesions. Positive test results should be followed up with complete diagnostic testing to treat precancerous lesions and diagnose patients at earlier stages of cancer, thereby increasing overall survival. More complex assays are designed to detect genetic changes in cells released from malignant and even premalignant lesions. This article provides information on the screening and diagnostic tests available for CRC detection as well as the advantages and disadvantages of each.
Cancer Epidemiology, Biomarkers & Prevention, Nov 1, 2008
Psychosocial constructs have been used to predict colorectal cancer screening and are frequently ... more Psychosocial constructs have been used to predict colorectal cancer screening and are frequently targeted as intermediate outcomes in behavioral intervention studies. Few studies have conducted analyses to adequately test construct validity. The psychometric analyses undertaken with U.S. populations of 16 theory-based, colorectal cancer screening items designed to measure five factors (salience-coherence, cancer worries, perceived susceptibility, response efficacy, and social influence) are an exception. The current investigation replicates previous work by examining factor validity and invariance in a random sample of Ontario, Canada residents. A survey instrument was administered to 1,013 Ontario male (49%) and female (51%) residents randomly selected by the Canada Survey Sample. Single-group confirmatory factor analyses (CFA) assessed data fit to the proposed five-factor model for males and females separately, and then a multigroup CFA evaluated if the factor structure was invariant for men and women. The five-factor model provided good fit for both males and females. Tests for factorial invariance between sexes, however, found mixed results. C 2 difference test was significant (P = 0.025); however, #RMSEA = 0.0001. Factor loadings were similar by sex except for two social influence items, with item frequency distributions suggesting an extreme response style, in females, on these items. Overall, the single-group and multigroup CFA results support factorial validity and partial invariance of the five-factor model first identified in the U.S. populations. The items can be used to evaluate and compare psychosocial correlates across U.S. and Canadian samples. Additional research is needed to show invariance for other ethnocultural and national subgroups.
Interactive Journal of Medical Research
Canadian Journal of Cardiology, 2018
Canadian Journal of Cardiology, 2015
Cognitive-behavioral group therapy: For specific problems and populations.
This chapter describes the Risk Adaptation Model (RAM), an orienting model in cognitive-behaviora... more This chapter describes the Risk Adaptation Model (RAM), an orienting model in cognitive-behavioral group therapy that provides medical patients a collaborative–empirical method of mapping health pathways defined by individual and group values. By providing patients a foundation in mindfulness practice, a healing environment, and an integrative field in which group exchanges yield new insights and changes in behavior, the model enables individual members and the group, as a whole, to function in a more integrated manner. Lastly, the RAM provides the medical patients of the group a structure for managing personal and group expectancies as important tools in deriving sound decision making and successful personal change. (PsycINFO Database Record (c) 2015 APA, all rights reserved)
Journal of Clinical Oncology, Feb 20, 2022
75 Background: Recruitment for most exercise trials is challenging and often hindered by particip... more 75 Background: Recruitment for most exercise trials is challenging and often hindered by participants’ inability to travel to the study centre and/or unwillingness to be randomized. Thus, patients in exercise randomized controlled trials (RCTs) are highly selected and may not reflect real-world experiences. Our objectives were to compare baseline characteristics and outcomes of men who agreed to participate in a preference-based trial (PREF) compared to a RCT of the same exercise interventions. Methods: A 2-arm multicentre PREF trial was conducted concurrently with a 2-arm RCT. Participants were men on ADT who were treated at 2 academic and 2 community hospitals in Canada and selected to engage in a group-based in-centre exercise intervention (GROUP) or a home-based exercise program (HOME). All participants underwent aerobic and resistance training 4-5 days per week for 6 months. Co-primary outcomes included fatigue (FACT-F) and the 6-minute walk test (6MWT). Differences at baseline between the two trials were compared using ANOVA. Analysis of covariance with adjustment for baseline value was used to assess differences in the study outcomes between the two trials and between exercise arms. Results: 56 participants (mean age 70 y) consented and selected to participate in GROUP (n = 18) or HOME (n = 38). Recruitment rate was 21.5%. Retention at 6 months in the PREF and RCT was 72.7% and 50%, respectively. No significant differences were observed in baseline characteristics between participants of the two trials. Adherence was met by 60% of participants in PREF. Participants in PREF exhibited a 28.7-metre increase (better) in the 6MWT at 6 months compared to RCT participants ( p = 0.20). Additionally, participants in PREF demonstrated less time (better) to complete 5 chair stands (mean change: -1.24s) at 6 months relative to participants in the RCT irrespective of exercise mode ( p = 0.06). HOME participants in the PREF completed the 5 chair stands faster (mean change: -2.19s) compared to HOME participants in the RCT (p = 0.01). Similarly, GROUP participants in the RCT required less time (mean change: -2.11s) for 5 chair stands compared to GROUP participants in the PREF (p = 0.04). Hip circumference was higher (worse) at 6 months in PREF participants (mean change: +2.95cm) compared to their RCT counterparts (p = 0.02). Although fatigue was not significantly different between participants in the two studies at 6 months, GROUP participants in the RCT experienced worse fatigue (mean change: -6.93) compared to those who selected GROUP (p = 0.03). Conclusions: Allowing participants to select the exercise intervention of their preference may improve retention and ameliorate functional declines as a result of ADT. Further studies that assess the effects of preference-based trials on clinical outcomes are warranted. Clinical trial information: NCT03335631.
JMIR Research Protocols, May 12, 2023
Background: Exposures to "traumatic" events are widespread and can cause posttraumatic stress dis... more Background: Exposures to "traumatic" events are widespread and can cause posttraumatic stress disorder (PTSD). Cognitive behavioral therapy and eye movement desensitization and reprocessing (EMDR) are frequently used and validated behavioral PTSD treatments. Despite demonstrated effectiveness, highly upsetting memory reactions can be evoked, resulting in extensive distress and, sometimes, treatment dropout. In recent years, multiple treatment approaches have aimed at reducing such upsetting memory reactions to traumatic memories while therapeutic progress proceeds. One of these methods, the flash technique (FT), a modification of standard EMDR (S-EMDR), appears effective in distressing memory reduction. This study will examine FT-EMDR and S-EMDR efficacies when both methods are delivered via web-based video. Objective: This study aims to assess the relative efficacy of (web-based) FT-EMDR versus S-EMDR in reducing the PTSD symptoms, anxieties, and depression associated with traumatic memories at postintervention and 1-month follow-up. Methods: This double-blinded, web-based, 2-arm randomized controlled trial will employ self-report outcomes. A total of 90 participants will be identified from the web-based CloudResearch platform and randomly allocated to the experimental or comparison group. Inclusion criteria are as follows: (1) approved for engagement by the CloudResearch platform; (2) 25-60 years of age; (3) residing in Canada or the United States; (4) a recalled disturbing memory of an event >2 years ago that has not repeated and was moderately or more upsetting during occurrence; (5) memory moderately or more upsetting at baseline and not linked to an earlier memory that is equally or more than equally disturbing. Exclusion criteria are bipolar disorder, borderline personality disorder, obsessive-compulsive disorder, schizophrenia, substance abuse or addiction in the past 3 months, suicidal ideation, and suicide attempt in the past 6 months. Interventions include guided video instruction of full FT or guided video of EMDR.
BACKGROUND Exposures to “traumatic” events are widespread and can cause posttraumatic stress diso... more BACKGROUND Exposures to “traumatic” events are widespread and can cause posttraumatic stress disorder (PTSD). Cognitive behavioral therapy and eye movement desensitization and reprocessing (EMDR) are frequently used and validated behavioral PTSD treatments. Despite demonstrated effectiveness, highly upsetting memory reactions can be evoked, resulting in extensive distress and, sometimes, treatment dropout. In recent years, multiple treatment approaches have aimed at reducing such upsetting memory reactions to traumatic memories while therapeutic progress proceeds. One of these methods, the flash technique (FT), a modification of standard EMDR (S-EMDR), appears effective in distressing memory reduction. This study will examine FT-EMDR and S-EMDR efficacies when both methods are delivered via web-based video. OBJECTIVE This study aims to assess the relative efficacy of (web-based) FT-EMDR versus S-EMDR in reducing the PTSD symptoms, anxieties, and depression associated with traumatic memories at postintervention and 1-month follow-up. METHODS This double-blinded, web-based, 2-arm randomized controlled trial will employ self-report outcomes. A total of 90 participants will be identified from the web-based CloudResearch platform and randomly allocated to the experimental or comparison group. Inclusion criteria are as follows: (1) approved for engagement by the CloudResearch platform; (2) 25-60 years of age; (3) residing in Canada or the United States; (4) a recalled disturbing memory of an event >2 years ago that has not repeated and was moderately or more upsetting during occurrence; (5) memory moderately or more upsetting at baseline and not linked to an earlier memory that is equally or more than equally disturbing. Exclusion criteria are bipolar disorder, borderline personality disorder, obsessive-compulsive disorder, schizophrenia, substance abuse or addiction in the past 3 months, suicidal ideation, and suicide attempt in the past 6 months. Interventions include guided video instruction of full FT or guided video of EMDR. Outcome measures are as follows: Primary outcome is PTSD symptoms that are measured by the PTSD Checklist for DSM-5 (Diagnostic and Statistical Manual of Mental Disorders-5) at 1-month follow-up. Secondary outcomes are State Anxiety subscale of State-Trait Anxiety Inventory at baseline, postintervention, and 1-month follow-up; Trait Anxiety subscale of State-Trait Anxiety Inventory; depression (Patient Health Questionnaire-9); and Positive and Negative Affect Schedule measured at 1-month follow-up. RESULTS If, at 1-month follow-up, the web-based FT-EMDR intervention is more effective in reducing PTSD symptoms (as measured by the PTSD Checklist for DSM-5) than EMDR, it may help reduce traumatic memory distress in multiple contexts. CONCLUSIONS This randomized controlled trial will advance current understandings of PTSD symptoms and interventions that target traumatic memory–related distress. CLINICALTRIAL ClinicalTrials.gov NCT05262127; https://clinicaltrials.gov/ct2/show/NCT05262127
Archives of Physical Medicine and Rehabilitation, Aug 1, 1994
TJ. Functional competence of communitydwelling persons with multiple sclerosis using the assessme... more TJ. Functional competence of communitydwelling persons with multiple sclerosis using the assessment of motor and process skills. Arch Phys Med Rebabil 1994:75:843-51. l The Assessment of Motor and Process Skills (AMPS) is an observational measure of functional competence in instrumental activities of daily living (IADL) that was designed to overcome the limitations of self reports and proxy reports. The AMPS allows simultaneous evaluation of the underlying motor and process (organizational/ adaptive) skills necessary for competent task performance. We examined the IADL performance of 22 communitydwelling patients with mild to moderate MS in comparison to nondisabled subjects matched for age and gender. Functional competence of the MS subjects, as measured by the AMPS, was poorer than that of the control group. Many MS subjects who would not have been expected to have IADL difficulties on the basis of ratings of neurologic impairment were impaired in their IADL performance. For some patients, IADL impairment reflected deficits in their motor and process skills, whereas for others, process skill impairments alone were responsible for deficient task performance.
BMJ Open, Nov 1, 2022
Objectives The study objective was to understand the barriers and facilitators to healthy active ... more Objectives The study objective was to understand the barriers and facilitators to healthy active living in South Asian families living in Canada. Design Semi-structured interviews of 30-60-minute duration with South Asian women with young families, and analysed using a thematic analytical approach. Setting Community-dwelling South Asian women interviewed in the home environment or by phone. Participants Fifteen married South Asian women (mean age=34.2 years) living in the Peel region of Ontario, Canada, with at least 1 child under the age of 5 years. The majority of women had immigrated to Canada (13/15), during a 5-10-year interval preceding interviews. Results 57 different codes were derived from 18 interview hours, and further evaluated through member checking. The top three barriers to healthy eating were: (1) not having enough time for healthy food preparation, (2) lack of knowledge about what is healthy eating and (3) viewing healthy eating as a matter of engaging in time limited dieting. These barriers were addressed with: (1) knowledge and awareness of healthy eating, (2) clear goal setting, (3) access to fresh vegetables and fruits and (4) better arrangements and more time for food preparation. The top five barriers to physical activity were: (1) not enough time and energy, (2) competing priorities, (3) lack of childcare, (4) lack of family-engaging exercise and (5) limited access to interesting exercise programming. These barriers were addressed by: (1) experiencing exercise as enjoyable and stress releasing, (2) commitments to walking exercise, (3) use of an electronic exercise-tracking device, (4) offspring exercise supported by spouse and family and (5) success stories about exercise from others. Conclusions Barriers to healthy active living in South Asian women with young families can be addressed with facilitators that stimulate clear goal setting and healthy food preparation skills, and exercise formats that engage mothers and offspring, with or without exercise tracking.
Post-traumatic stress disorder is a major public health concern with a lifetime prevalence rate o... more Post-traumatic stress disorder is a major public health concern with a lifetime prevalence rate of 6.1-9.2% in North America. PTSD is known to alter the autonomic nervous system leading to chronic sympathetic arousal including heightened anxiety and hypervigilance. Pupillometry offers a quick and accessible measure of autonomic nervous system imbalances characteristic of PTSD. This study investigates the utility of pupillometry as a biomarker to detect PTSD in a sample of 39 adults with (n = 22) and without (n = 17) PTSD. Participants viewed a 25-minute computer protocol consisting of 5-minute rest phase, 10-minute negative emotionally valent images, and 10-minute guided meditation. We relied on a time-frequency analysis to represent the pupillary responses of two different groups (PTSD-affected individuals and healthy-control subjects). These data were then employed with a CNN network to learn a prediction model. Individuals with PTSD demonstrated increased pupil dilation across the entire protocol. The final outcome revealed an accuracy of 81.09% which indicates the feasibility of using this approach to detecting participants with PTSD in an automated way. Findings from this research have important implications for clinical mental health assessment, diagnostics and treatment.
Canadian Journal of Cardiology, Oct 1, 2019
Canadian Journal of Cardiology, Oct 1, 2019
International journal of clinical cardiology, Sep 30, 2017
Canadian Journal of Neurological Sciences, Feb 1, 1994
JMIR mental health, Dec 2, 2020
Journal of the American College of Cardiology, Apr 1, 2016
Background: Atrial Fibrillation (AF) ablation is a common intervention for patient suffering from... more Background: Atrial Fibrillation (AF) ablation is a common intervention for patient suffering from drug refractory symptomatic AF. Unfortunately a number of patients require repeat procedures to ensure success. Objective software-based demarcation of ablation lesions based on catheter stability may improve procedural success. The purpose of this study was to test whether this strategy improves outcomes of Pulmonary Vein Antral Isolation (PVAI) compared to subjective lesion demarcation by the operator. Methods: Patients were divided into 2 groups, those who had the procedure done using VISITAG™ Technology (Group A), and age-gender matched control patients ablated during a 12 month period prior to the introduction of this technology (Group B). Baseline, procedure and outcome data were obtained for 97 patients ([40 in group A] and [57 in group B]). Mean age for Groups A and B were 63.3±8.51 and 60±13.1 (p=0.01) respectively. In all patients PVAI was guided by intracardiac ECHO and a circular mapping catheter using CARTO3 3D mapping system, and a Thermocool ablation catheter. In Group A lesions were demarcated automatically at 3mm/7sec VISITAG setting, while in Group B Lesions were demarcated by the operator. ECG was performed at 1, 3, 6, and 12 months. Recurrences ≤ 3 months were considered Early (ER), while recurrences after 3 months were considered Late (LR). Using survival analysis, rates of ER and LR stratified by AF type [Paroxysmal AF (PAF) vs. Non-PAF (NPAF)] were compared. Only outcomes during the first 12 months of follow-up were compared. Results: The rates of ER and LR were lower in patients in Group A vs. Group B (30.0% vs. 52.6%, p=0.05 and 20.0% vs. 42.1%, p=0.05 respectively). Furthermore, patients with PAF had dramatically lower ER rate in Group A vs. Group B (16.7% vs. 48.4%, p=0.04), while NPAF patients had a significant improvement in LR (18.6% vs. 48.0%, p=0.003). Procedure, and fluoroscopy time differences were not significant. Conclusions: Objective demarcation of lesions based on catheter stability during PVAI procedures results in a significant improvement in AF recurrence rates during 12 months of follow-up. Technologies enabling this strategy warrant further clinical evaluation.
Canadian Family Physician, Feb 1, 2009
Colorectal cancer (CRC) is the third most common cancer in the United States. A reduction in cumu... more Colorectal cancer (CRC) is the third most common cancer in the United States. A reduction in cumulative mortality occurs when patients are routinely screened by fecal occult blood tests (FOBT) and early lesions are removed. These point-of-care tests detect minute amounts of blood released from precancerous and cancerous colon lesions. Positive test results should be followed up with complete diagnostic testing to treat precancerous lesions and diagnose patients at earlier stages of cancer, thereby increasing overall survival. More complex assays are designed to detect genetic changes in cells released from malignant and even premalignant lesions. This article provides information on the screening and diagnostic tests available for CRC detection as well as the advantages and disadvantages of each.
Cancer Epidemiology, Biomarkers & Prevention, Nov 1, 2008
Psychosocial constructs have been used to predict colorectal cancer screening and are frequently ... more Psychosocial constructs have been used to predict colorectal cancer screening and are frequently targeted as intermediate outcomes in behavioral intervention studies. Few studies have conducted analyses to adequately test construct validity. The psychometric analyses undertaken with U.S. populations of 16 theory-based, colorectal cancer screening items designed to measure five factors (salience-coherence, cancer worries, perceived susceptibility, response efficacy, and social influence) are an exception. The current investigation replicates previous work by examining factor validity and invariance in a random sample of Ontario, Canada residents. A survey instrument was administered to 1,013 Ontario male (49%) and female (51%) residents randomly selected by the Canada Survey Sample. Single-group confirmatory factor analyses (CFA) assessed data fit to the proposed five-factor model for males and females separately, and then a multigroup CFA evaluated if the factor structure was invariant for men and women. The five-factor model provided good fit for both males and females. Tests for factorial invariance between sexes, however, found mixed results. C 2 difference test was significant (P = 0.025); however, #RMSEA = 0.0001. Factor loadings were similar by sex except for two social influence items, with item frequency distributions suggesting an extreme response style, in females, on these items. Overall, the single-group and multigroup CFA results support factorial validity and partial invariance of the five-factor model first identified in the U.S. populations. The items can be used to evaluate and compare psychosocial correlates across U.S. and Canadian samples. Additional research is needed to show invariance for other ethnocultural and national subgroups.
Interactive Journal of Medical Research
Canadian Journal of Cardiology, 2018
Canadian Journal of Cardiology, 2015
Cognitive-behavioral group therapy: For specific problems and populations.
This chapter describes the Risk Adaptation Model (RAM), an orienting model in cognitive-behaviora... more This chapter describes the Risk Adaptation Model (RAM), an orienting model in cognitive-behavioral group therapy that provides medical patients a collaborative–empirical method of mapping health pathways defined by individual and group values. By providing patients a foundation in mindfulness practice, a healing environment, and an integrative field in which group exchanges yield new insights and changes in behavior, the model enables individual members and the group, as a whole, to function in a more integrated manner. Lastly, the RAM provides the medical patients of the group a structure for managing personal and group expectancies as important tools in deriving sound decision making and successful personal change. (PsycINFO Database Record (c) 2015 APA, all rights reserved)
Journal of Clinical Oncology, Feb 20, 2022
75 Background: Recruitment for most exercise trials is challenging and often hindered by particip... more 75 Background: Recruitment for most exercise trials is challenging and often hindered by participants’ inability to travel to the study centre and/or unwillingness to be randomized. Thus, patients in exercise randomized controlled trials (RCTs) are highly selected and may not reflect real-world experiences. Our objectives were to compare baseline characteristics and outcomes of men who agreed to participate in a preference-based trial (PREF) compared to a RCT of the same exercise interventions. Methods: A 2-arm multicentre PREF trial was conducted concurrently with a 2-arm RCT. Participants were men on ADT who were treated at 2 academic and 2 community hospitals in Canada and selected to engage in a group-based in-centre exercise intervention (GROUP) or a home-based exercise program (HOME). All participants underwent aerobic and resistance training 4-5 days per week for 6 months. Co-primary outcomes included fatigue (FACT-F) and the 6-minute walk test (6MWT). Differences at baseline between the two trials were compared using ANOVA. Analysis of covariance with adjustment for baseline value was used to assess differences in the study outcomes between the two trials and between exercise arms. Results: 56 participants (mean age 70 y) consented and selected to participate in GROUP (n = 18) or HOME (n = 38). Recruitment rate was 21.5%. Retention at 6 months in the PREF and RCT was 72.7% and 50%, respectively. No significant differences were observed in baseline characteristics between participants of the two trials. Adherence was met by 60% of participants in PREF. Participants in PREF exhibited a 28.7-metre increase (better) in the 6MWT at 6 months compared to RCT participants ( p = 0.20). Additionally, participants in PREF demonstrated less time (better) to complete 5 chair stands (mean change: -1.24s) at 6 months relative to participants in the RCT irrespective of exercise mode ( p = 0.06). HOME participants in the PREF completed the 5 chair stands faster (mean change: -2.19s) compared to HOME participants in the RCT (p = 0.01). Similarly, GROUP participants in the RCT required less time (mean change: -2.11s) for 5 chair stands compared to GROUP participants in the PREF (p = 0.04). Hip circumference was higher (worse) at 6 months in PREF participants (mean change: +2.95cm) compared to their RCT counterparts (p = 0.02). Although fatigue was not significantly different between participants in the two studies at 6 months, GROUP participants in the RCT experienced worse fatigue (mean change: -6.93) compared to those who selected GROUP (p = 0.03). Conclusions: Allowing participants to select the exercise intervention of their preference may improve retention and ameliorate functional declines as a result of ADT. Further studies that assess the effects of preference-based trials on clinical outcomes are warranted. Clinical trial information: NCT03335631.