An Evaluation of Sex Differences in Patients With Chronic Pain Undergoing an Interdisciplinary Pain Treatment Program

Further evidence that peritraumatic 17β-estradiol levels influence chronic posttraumatic pain outcomes in women, data from both humans and animals

ABSTRACT

Chronic posttraumatic pain (CPTP) is common after traumatic stress exposure (TSE) and disproportionately burdens women. We previously showed across 3 independent longitudinal cohort studies that, in women, increased peritraumatic 17β-estradiol (E2) levels were associated with substantially lower CPTP over 1 year. Here, we assessed this relationship in a fourth longitudinal cohort and also assessed the relationship between E2 and CPTP at additional time points post-TSE. Furthermore, we used a well-validated animal model of TSE to determine whether exogenous E2 administration protects against mechanical hypersensitivity. Using nested samples and data from the Advancing Understanding of RecOvery afteR traumA study (n = 543 samples, 389 participants), an emergency department-based prospective study of TSE survivors, we assessed the relationship between circulating E2 levels and CPTP in women and men using multivariate repeated-measures mixed modeling. Male and ovariectomized female Sprague Dawley rats were exposed to TSE and administered E2 either immediately after or 3 days post-TSE. Consistent with previous results, we observed an inverse relationship between peritraumatic E2 and longitudinal CPTP in women only (β = -0.137, P = 0.033). In animals, E2 protected against mechanical hypersensitivity in female ovariectomized rats only if administered immediately post-TSE. In conclusion, peritraumatic E2 levels, but not those at post-TSE time points, predict CPTP in women TSE survivors. Administration of E2 immediately post TSE protects against mechanical hypersensitivity in female rats. Together with previous findings, these data indicate that increased peritraumatic E2 levels in women have protective effects against CPTP development and suggest that immediate post-TSE E2 administration in women could be a promising therapeutic strategy for reducing risk of CPTP.

Which patients with chronic low back pain respond favorably to multidisciplinary rehabilitation? A secondary analysis of a randomized controlled trial

OBJECTIVES

The aim of this study was to identify prognostic variables at baseline associated with being responding favorably to multidisciplinary rehabilitation in patients with chronic low back pain (CLBP).

METHODS

A responder analysis was conducted based on data from a randomized controlled trial with 26-week follow-up including 165 patients with CLBP treated at a Danish multidisciplinary rehabilitation center. Patients were dichotomized into responders and non-responders based on the outcome of a minimal clinically important difference of six points on the Oswestry Disability Index. The associations between prognostic variables and responders were analyzed using logistic regression.

RESULTS

A total of 139 patients completed the study, of which 42% were classified as responders. Sex and employment status were statistically significant, with a decreased odds ratio (OR) of being a responder found for males compared to females (OR = 0.09, 95% CI = 0.02-0.48) and for being on temporary or permanent social benefits (OR = 0.28, 95% CI = 0.10-0.75) compared to being self-supporting or receiving retirement benefits. Statistically significant interaction (OR = 8.84, 95% CI = 1.11-70.12) was found between males and being on temporary or permanent social benefits.

CONCLUSIONS

In patients with CLBP, female patients as well as patients who were self-supporting or receiving retirement benefits were significantly more likely than male patients or patients on temporary or permanent social benefits to be a responder to multidisciplinary rehabilitation.

Sex Differences in Neurological Emergencies Presenting to Multiple Urban Level 1 Trauma Centers

Previous studies have suggested that there are sex differences in the treatment and outcome of neurological emergencies; however, research identifying the role these sex differences play in the management of neurological emergencies is lacking. More knowledge of the way sex factors into the pathophysiology of neurological emergencies will be helpful in improving outcomes for these patients. The aim of this cross-sectional study was to assess the prevalence and management of neurological emergencies while evaluating sex differences in the diagnosis and treatment of these emergencies. We analyzed a cohort of 530 adult patients from four level 1 trauma centers over a period of 4 weeks who had a chief complaint of a neurological emergency, including seizures, cerebrovascular events, headache disorders, traumatic brain injuries, and central nervous system infections. Among patients with neurological emergencies, a significantly lower proportion of female patients underwent neurosurgery and were admitted to the intensive care unit compared to male patients, but there were no significant differences between sexes in the time of symptom onset, type of hospital transportation, amount of neuroimaging performed, admission rates, hospital length of stay, and disposition from the emergency department. Although female patients were more likely to have a chief complaint of headache compared to traumatic injuries in male patients, this was not statistically significant. A significantly higher proportion of female patients had health insurance coverage than male patients.

Interdisciplinary Multimodal Pain Rehabilitation in Patients with Chronic Musculoskeletal Pain in Primary Care-A Cohort Study from the Swedish Quality Registry for Pain Rehabilitation (SQRP)

Chronic pain is a major public health issue. Mounting evidence suggests that interdisciplinary multimodal pain rehabilitation programs (IMMRPs) performed in specialist pain care are an effective treatment for patients with chronic pain, but the effects of such treatment if performed in primary care settings have been less studied. The aims of this pragmatic study were to (1) describe characteristics of patients participating in IMMRPs in primary care; (2) examine whether IMMRPs in primary care improve pain, disability, quality of life, and sick leave 1-year post discharge in patients with chronic pain; and (3) investigate if outcomes differ between women and men. Data from 744 (645 women and 99 men, age range 18-65 years) patients with non-malignant chronic pain included in the Swedish Quality Registry for Pain Rehabilitation Primary Care were used to describe patient characteristics and changes in health and sick leave. At 1-year follow-up, the patients had improved significantly (p < 0.01) in all health outcome measures and had reduced sick leave except in men, where no significant change was shown in physical activity level. This study indicates that MMRPs in primary care improved pain and physical and emotional health and reduced sick leave, which was maintained at the 1-year follow-up.

Biopsychosocial Approach in Identifying Risk Factors of Kinesiophobia in Persons with Subacromial Pain Syndrome and Developing a Clinical Prediction Tool

Introduction

Although the negative effects of kinesiophobia on functional status in subacromial pain syndrome (SAPS) patients are clearly demonstrated, no study examines the risk factors of kinesiophobia in individuals with SAPS from a biopsychosocial perspective. The present study aims to determine the risk factors of kinesiophobia in individuals with SAPS using a biopsychosocial approach. This study also aims to explore the compounding effects of multiple associative risk factors by developing a clinical prediction tool to identify SAPS patients at higher risk for kinesiophobia.

Materials and methods

This cross-sectional study included 549 patients who were diagnosed with SAPS. The Tampa-Scale of Kinesiophobia (TSK) was used to assess kinesiophobia. Visual analog scale (VAS), The Shoulder Pain and Disability Index (SPADI), Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, the presence of metabolic syndrome, using any non-steroidal anti-inflammatory drugs, Pain Catastrophizing Scale (PCS), Illness Perception Questionnaire-revised (IPQ-R), Hospital Anxiety and Depression Scale (HADS), behavioral pattern of the patient, sociodemographic characteristics, and treatment expectancy were outcome measures.

Results

Thirteen significant risk factors of having kinesiophobia were: VASat rest (≥ 5.2), VASduring activity (≥ 7.1), DASH (≥ 72.1), presence of metabolic syndrome, PCShelplessness (≥ 16.1), IPQ-Rpersonal control (≤ 17.1), IPQ-Rtreatment control (≤ 16.3), HADSdepression (≥ 7.9), avoidance behavior type, being female, educational level (≤ high school), average hours of sleep (≤ 6.8), and treatment expectancy (≤ 6.6). The presence of seven or more risk factors increased the probability of having high level of kinesiophobia from 34.3 to 51%.

Conclusions

It seems necessary to address these factors, increase awareness of health practitioners and individuals.

Level of evidence

Level IV.

What factors predict outcome from an inpatient multidisciplinary chronic pain service? A prospective cohort study

Objective To identify baseline factors associated with outcomes from an inpatient multidisciplinary pain management program (PMP) located in a bicultural area of Aotearoa New Zealand. Methods A prospective cohort study was undertaken involving 164 people with chronic pain who attended the PMP. Demographic, clinical, and psychosocial measures were obtained at baseline, whereas clinical and psychosocial outcome measures were also obtained at program discharge and 3-month follow up (N  = 100). Multivariate analyses were used to determine baseline demographic variables that were associated with outcomes at discharge and follow up. Results Being male and working full-time were associated with poorer outcomes in select measures at discharge. At the 3-month follow up, Māori ethnicity, working full-time, being retired or unemployed, or having chronic widespread pain were associated with poorer outcomes for some measures, whereas those with rheumatoid arthritis had greater self-efficacy. Conclusions Sex, ethnicity, employment status, and patient condition impact clinical outcomes from the program and in the time from discharge to follow up. Program content and/or delivery should be altered to promote more equitable outcomes for all patients in the long term.

Pilot study on the effects of a culturally-sensitive and standard pain neuroscience education for Hausa-speaking patients with chronic neck pain

PURPOSE

To pilot feasibility and assess preliminary effectiveness of standard and culture-sensitive Pain Neuroscience Education (PNE) among Hausa-speaking patients with Chronic Neck Pain (CNP).

METHODS

Adverts (online & clinic-based) were used to recruit Hausa-speaking patients with nonspecific CNP in Kano, Nigeria. Selected participants were randomized to culture-sensitive PNE (CSPNE), standard PNE (PNE), or control groups. Each group received bi-weekly sessions of exercise therapy for 6 weeks. Two sessions of PNE plus a home-based session were administered before exercise therapy in the PNE groups. Primary (pain-intensity and disability) and secondary (pain-knowledge, pain catastrophizing, and quality of life) outcomes were measured. The study was pre-registered (PACTR201902788269426).

RESULTS

Fifty-three (out of 64) participants met the inclusion criteria. The majority of them were recruited through radio adverts (83%). Interventions were successfully administered and data collection was completed for the participants. About 15% and 17% drop-out rate was recorded before intervention (post-randomization) and during follow-up, respectively. Main results indicated that significant within-group improvements in disability and pain knowledge scores were found in favor of the PNE groups.

CONCLUSION

Culture-sensitive and standard PNE plus exercise therapy are feasible for Hausa patients with CNP, and current findings indicate support for reducing disability and increasing pain knowledge among them.Implications for rehabilitationBoth standard PNE and culture-sensitive PNE are feasible for administration as interventions for Hausa-speaking patients with CNP.Radio adverts may be necessary for patients recruitment in addition to specialists' referrals.Culturally sensitive PNE materials may be more desirable as an intervention option due to the low literacy level among the Hausa population.

Sex and gender differences in pain

Chronic pain affects 20% of adults and is one of the leading causes of disability worldwide. Women and girls are disproportionally affected by chronic pain. About half of chronic pain conditions are more common in women, with only 20% having a higher prevalence in men. There are also sex and gender differences in acute pain sensitivity. Pain is a subjective experience made up of sensory, cognitive, and emotional components. Consequently, there are multiple dimensions through which sex and gender can influence the pain experience. Historically, most preclinical pain research was conducted exclusively in male animals. However, recent studies that included females have revealed significant sex differences in the physiological mechanisms underlying pain, including sex specific involvement of different genes and proteins as well as distinct interactions between hormones and the immune system that influence the transmission of pain signals. Human neuroimaging has revealed sex and gender differences in the neural circuitry associated with pain, including sex specific brain alterations in chronic pain conditions. Clinical pain research suggests that gender can affect how an individual contextualizes and copes with pain. Gender may also influence the susceptibility to develop chronic pain. Sex and gender biases can impact how pain is perceived and treated clinically. Furthermore, the efficacy and side effects associated with different pain treatments can vary according to sex and gender. Therefore, preclinical and clinical research must include sex and gender analyses to understand basic mechanisms of pain and its relief, and to develop personalized pain treatment.

Sex differences in interdisciplinary pain rehabilitation outcomes: a systematic review

OBJECTIVES

Interdisciplinary pain rehabilitation programs (IPRPs) are evidence-based treatments for chronic pain. Previous research has demonstrated that initial presentations of adult men and women admitted to IPRPs differ, but less is known about sex differences in IPRP treatment outcomes. To summarize and synthesize the current literature base on this topic, a systematic literature review was conducted that asked: are sex differences present in participant outcomes upon completion of interdisciplinary pain rehabilitation programs for cisgender patients? Four core domains of outcome measures were assessed: depression, pain catastrophizing, pain interference, and pain intensity/severity.

METHODS

Relevant studies meeting inclusion criteria were identified using a computer-aided search of the following electronic bibliographic databases: PubMed (MEDLINE), EMBASE, PsycINFO, CENTRAL (via Wiley Online Library), and CINAHL (via EBSCOhost). The reference list of relevant studies identified in the electronic searches was also screened to identify further studies.

RESULTS

This review concluded that most studies did not find any differences related to sex using the four outcome measures included in this review. This implies that specific considerations based on sex may not be needed when providing interdisciplinary pain rehabilitation.

CONCLUSIONS

Future research directions include comparison of additional outcome measures and exploring sex and gender issues in IPRP treatment in other formats than as a simple dichotomous variable.

Outcomes of a Comprehensive Pain Rehabilitation Program for Patients With Fibromyalgia

OBJECTIVE

To analyze opioid intake interference with psychological, well-being, and functional outcomes and medication tapering in patients with fibromyalgia admitted to the Mayo Clinic Pain Rehabilitation Program (MCPRP) in Florida.

PATIENTS AND METHODS

A retrospective study on MCPRP outcomes was conducted. We reviewed the health records of 150 patients with fibromyalgia who participated in the program from May 1, 2014, to May 1, 2015. All patients were asked to fill out a survey at admission to and dismissal from the program. Surveys contained questions from the numeric pain score, Multidimensional Pain Inventory (perceived life control and interference of pain subscales), Center for Epidemiological Studies-Depression Scale, Pain Catastrophizing Scale, 36-Item Short-Form Health Status Survey (general health perceptions subscale), and Pain Self-Efficacy Questionnaire. A medical record review identified categories and number of medications at program admission and dismissal. Patients were divided in 2 groups: those whose concomitant medication did not include opioids at admission (no opioids group) and those whose concomitant medication included opioids at admission (opioids group).

RESULTS

By dismissal from the MCPRP, patients with fibromyalgia in the no opioids group had a significant (P<.05) improvement in all the self-reported scores. Medication, including opioids, were effectively tapered at a substantially higher percentage in the opioids group.

CONCLUSION

Benefit of the comprehensive pain rehabilitation program in patients with fibromyalgia was indicated by clinical improvements in pain severity, physical and emotional health, and functional capacity while successfully tapering medication. Opioid intake at admission may modify the program outcomes.

The anatomy of pain and suffering in the brain and its clinical implications

Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage. Chronic pain, with a prevalence of 20-30 % is the major cause of human suffering worldwide, because effective, specific and safe therapies have yet to be developed. It is unevenly distributed among sexes, with women experiencing more pain and suffering. Chronic pain can be anatomically and phenomenologically dissected into three separable but interacting pathways, a lateral 'painfulness' pathway, a medial 'suffering' pathway and a descending pain inhibitory pathway. One may have pain(fullness) without suffering and suffering without pain(fullness). Pain sensation leads to suffering via a cognitive, emotional and autonomic processing, and is expressed as anger, fear, frustration, anxiety and depression. The medial pathway overlaps with the salience and stress networks, explaining that behavioural relevance or meaning determines the suffering associated with painfulness. Genetic and epigenetic influences trigger chronic neuroinflammatory changes which are involved in transitioning from acute to chronic pain. Based on the concept of the Bayesian brain, pain (and suffering) can be regarded as the consequence of an imbalance between the two ascending and the descending pain inhibitory pathways under control of the reward system. The therapeutic clinical implications of this simple pain model are obvious. After categorizing the working mechanisms of each of the available treatments (pain killers, psychopharmacology, psychotherapy, neuromodulation, psychosurgery, spinal cord stimulation) to 1 or more of the 3 pathways, a rational combination can be proposed of activating the descending pain inhibitory pathway in combination with inhibition of the medial and lateral pathway, so as to rebalance the pain (and suffering) pathways.

INYBI: A New Tool for Self-Myofascial Release of the Suboccipital Muscles in Patients With Chronic Non-Specific Neck Pain: A Randomized Controlled Trial

STUDY DESIGN

A randomized, single-blinded (the outcome assessor was unaware of participants' allocation group) controlled clinical trial.

OBJECTIVE

To investigate the effects of myofascial release therapy (MRT) over the suboccipital muscles, compared with self-MRT using a novel device, the INYBI tool, on pain-related outcomes, active cervical mobility, and vertical mouth opening, in adults with chronic non-specific neck pain (NSNP).

SUMMARY OF BACKGROUND DATA

MRT is used to manage chronic musculoskeletal pain conditions, with purported positive effects. The efficacy of self-MRT, compared with MRT, has been scarcely evaluated.

METHODS

Fifty-eight participants (mean age of 34.6 ± 4.7 yrs; range 21-40 yrs; 77.6% females, 22.4% males) with persistent NSNP agreed to participate, and were equally distributed into an INYBI (n = 29) or a control group (n = 29). Both groups underwent a single 5-minutes intervention session. For participants in the control group, MRT of the suboccipital muscles was performed using the suboccipital muscle inhibition technique, while those in the INYBI group underwent a self-MRT intervention using the INYBI device. Primary measurements were taken of pain intensity (visual analogue scale), local pressure pain sensitivity, as assessed with an algometer, and active cervical range-of-movement. Secondary outcomes included pain-free vertical mouth opening. Outcomes were collected at baseline, immediately after intervention and 45 minutes later.

RESULTS

The analysis of variance (ANOVAs) demonstrated no significant between-groups effect for any variable (all, P > 0.05). In the within-groups comparison, all participants significantly improved pain-related outcomes, and showed similar positive changes for mouth opening. Cervical range-of-movement- mainly increased after intervention for participants in the control group.

CONCLUSION

Both, MRT and self-MRT using the INYBI, are equally effective to enhance self-reported pain intensity, and local pressure pain sensitivity in chronic NSNP patients. For cervical mobility, MRT appears to be slighlty superior, compared with the INYBI, to achieve improvements in this population.

LEVEL OF EVIDENCE

2.

The gender context of pain

Pain is a major source of global suffering, with women bearing the greatest burden. Alongside biology, psychological and social factors, including gender, help explain these differences. However, there has been no direct attempt to develop a unified social psychological model of men and women's pain. By drawing on approaches to both gender and pain, a gender context model of pain is presented. It proposes that pain is partly influenced by the gender context in which it occurs, which operates at both individual and interpersonal levels. The model is used to structure an appraisal of the existing evidence around gender and pain, and explore whether the model helps explain why such variation occurs. It is argued that despite evidence for an association between gender and pain, there are empirical gaps that need to be addressed. Implications and directions for future investigations into sex, gender and pain are considered.