Gender role expectations of pain is associated with pain tolerance limit but not with pain threshold

Exploring the association of gender role expectations of pain and measures of pain sensitization in people with knee osteoarthritis: A cross-sectional study

OBJECTIVES

First, we explored the association between Gender Role Expectations of Pain (GREP), and psychophysical measures of sensitization in people with knee osteoarthritis (OA). Second, we explored whether the association differed by level of GREP items (high vs low scores).

DESIGN

We conducted secondary analyses of a cohort study. Those who were (i) age of ≥40, English or French speaking, ii) diagnosed with knee OA using American College of Rheumatology criteria and iii) consulting with an orthopedic surgeon were included. GREP items pertaining to pain sensitivity and pain endurance of the typical man or woman were rated by males and females respectively. Psychophysical tests consisted of pressure pain thresholds (PPTs), Temporal Summation (TS), and Conditioned Pain Modulation (CPM). Multiple linear regression models for males and females were run with GREP scores (independent variables) and psychophysical tests (dependent variables). Next models stratified on the median split of GREP scores were run. Models were adjusted for age, BMI, pain catastrophizing, anxio-depressive symptoms, and radiographic severity.

RESULTS

280 participants (57% females; age (SD): 63.9 (9.6) and BMI (SD): 31.3 (8.40)) were included. GREP pain sensitivity scores in males were associated with CPM values (β: 95% CI: 0.09 (0.01 to 0.17)). Males with low GREP pain sensitivity or pain endurance had very small to small positive associations with PPT and CPM values.

CONCLUSION

This first exploration of gendered pain sensitivity and pain endurance by males and females has small and clinically unimportant associations with measures of pain sensitization requiring further validation.

Gender roles as predictive factors on labor pain: a cross-sectional study

Labor is a complex, subjective experience, and all factors that influence pain should be considered to ensure a comprehensive evaluation. This study aimed to determine whether gender roles were predictive of labor pain. The study has a descriptive and cross-sectional design. It was carried out in a delivery room of a city hospital in Turkey between September 2019 and September 2020. The study sample consisted of 231 primiparous women presenting for labor and delivery. Data were gathered with a descriptive characteristics form, Visual Analogue Scale and The Bem Sex-Role Inventory. Descriptive statistics and simple regression analysis were employed to analyze the obtained data. Regression analysis demonstrated that gender roles were predictive of labor pain in the latent, active, and transitional stages, but not in the second stage. Gender roles were most responsible for labor pain in the latent phase. Results of the study revealed that gender roles may be useful variables to predict women's labor pain, and contributed to the relevant literature. Nurses and midwives offering care for labor pain should consider gender roles as a factor affecting labor pain. It is also necessary to individualize the supporting care given during labor.

Integrating mechanistic-based and classification-based concepts into perioperative pain management: an educational guide for acute pain physicians

Chronic pain begins with acute pain. Physicians tend to classify pain by duration (acute vs chronic) and mechanism (nociceptive, neuropathic and nociplastic). Although this taxonomy may facilitate diagnosis and documentation, such categories are to some degree arbitrary constructs, with significant overlap in terms of mechanisms and treatments. In clinical practice, there are myriad different definitions for chronic pain and a substantial portion of chronic pain involves mixed phenotypes. Classification of pain based on acuity and mechanisms informs management at all levels and constitutes a critical part of guidelines and treatment for chronic pain care. Yet specialty care is often siloed, with advances in understanding lagging years behind in some areas in which these developments should be at the forefront of clinical practice. For example, in perioperative pain management, enhanced recovery protocols are not standardized and tend to drive treatment without consideration of mechanisms, which in many cases may be incongruent with personalized medicine and mechanism-based treatment. In this educational document, we discuss mechanisms and classification of pain as it pertains to commonly performed surgical procedures. Our goal is to provide a clinical reference for the acute pain physician to facilitate pain management decision-making (both diagnosis and therapy) in the perioperative period.

The effect of unpredictability on the perception of pain: a systematic review and meta-analysis

ABSTRACT

Despite being widely assumed, the worsening impact of unpredictability on pain perception remains unclear because of conflicting empirical evidence, and a lack of systematic integration of past research findings. To fill this gap, we conducted a systematic review and meta-analysis focusing on the effect of unpredictability on pain perception. We also conducted meta-regression analyses to examine the moderating effect of several moderators associated with pain and unpredictability: stimulus duration, calibrated stimulus pain intensity, pain intensity expectation, controllability, anticipation delay, state and trait negative affectivity, sex/gender and age of the participants, type of unpredictability (intensity, onset, duration, location), and method of pain induction (thermal, electrical, mechanical pressure, mechanical distention). We included 73 experimental studies with adult volunteers manipulating the (un)predictability of painful stimuli and measuring perceived pain intensity and pain unpleasantness in predictable and unpredictable contexts. Because there are insufficient studies with patients, we focused on healthy volunteers. Our results did not reveal any effect of unpredictability on pain perception. However, several significant moderators were found, ie, targeted stimulus pain intensity, expected pain intensity, and state negative affectivity. Trait negative affectivity and uncontrollability showed no significant effect, presumably because of the low number of included studies. Thus, further investigation is necessary to clearly determine their role in unpredictable pain perception.

Predictors of lower knee function improvement two years after anterior cruciate ligament reconstruction

OBJECTIVES

The extent to which knee functions improve after anterior cruciate ligament reconstruction (ACLR) varies. This study aimed to determine the factors that affect lower knee function improvement after two years of ACLR.

METHODS

The study included 159 patients who underwent ACLR in the Indonesian ACL community between August 2018 and April 2020. The concomitant injury and graft types of ACLR were determined using patients' pre-surgical MRI and medical records. The five subscales of the knee injury and osteoarthritis outcome score (KOOS) were used to evaluate the patient at baseline, first year, and second year following ACLR. A linear mixed-effect model (LMEM) was used to predict the longitudinal improvement models for the five-subscales KOOS score after ACLR.

RESULTS

The LMEM predicted lower KOOS subscales scores improvements by 0.5 for QOL, 0.1 for symptom, ADL, and QOL, and 0.2 for sports/recreation, respectively, for a one score increase of age and time from injury to surgery. Male patients had higher KOOS subscale scores with the improvement of pain, symptom, and ADL by 5.7, 5.9, and 6.3 compared to female patients, respectively, while patients with patellar tendon grafts had lower improvement of KOOS score pain by 6.5 compared to hamstring tendon grafts.

CONCLUSION

As the age and time from injury to surgery increased, the KOOS subscales scores of QOL and symptoms, ADL, sports/recreation, and QOL decreased. Male patients reported higher KOOS subscales scores for pain, symptoms, and ADL, while patients with patella tendon grafts had a lower improvement in pain score.

The impact of biological sex in peripheral nerve blockade: A prospective pharmacodynamic, pharmacokinetic and morphometric study in volunteers

STUDY OBJECTIVE

The impact of biological sex in peripheral regional anaesthesia is largely unknown. We therefore designed a prospective study in volunteers to investigate the impact of biological sex on pharmacodynamic, pharmacokinetic and morphometric characteristics for peripheral nerve blockade.

METHODS

The initial study plan was powered to include 90 volunteers to find a difference of 35 min in duration of sensory block (primary outcome variable) with 80% power and alpha error at 5%. After discussions in ethical review, a pilot study of 2 x 12 volunteers from each sex were studied. Female and male volunteers received ultrasound guided nerve blockade with 3.0 mL ropivacaine 7.5 mg mL-1. Sensory duration of blockade, as the primary outcome, was evaluated by pinprick testing. Secondary outcomes were sensory onset time of blockade, pharmacokinetic characteristics and the visibility of ulnar nerves using ultrasound. Analyses included Mann-Whitney U-statistics with P<0.05 (two-sided) as significant.

RESULTS

After 24 participants, the median (IQR) duration of sensory blockade was 450 (420; 503) min in women and 480 (450; 510) min in men (P = 0.49). Sensory onset time of blockade, and ultrasound visibility of nerves were also similar between the study groups. The total drug exposure across time (AUC0-infinity) was significantly higher in women (P = 0.017). After a the planned power re-analysis after these 24 study paticipants, which suggested that > 400 subjects would be required with 80% power and alpha error of 5% to find significance for the primary outcome parameter for marginal differences, we terminated the study at this point.

CONCLUSIONS

We did not detect significant differences between female and male study participants in terms of pharmacodynamic and morphometric characteristics after ultrasound guided ulnar nerve blocks. Women did show significantly greater pharmacokinetic ropivacaine exposures. The results of this study indicate that peripheral regional block pharmacodynamic characteristics are independent of the biological sex, whereas pharmacokinetic parameters are sex-dependent.

Gender-based differential management of acute low back pain in the emergency department: A survey based on a clinical vignette

BACKGROUND

Women may receive suboptimal pain management compared with men, and this disparity might be related to gender stereotypes.

OBJECTIVES

To assess the influence of patient gender on the management of acute low back pain.

DESIGN

We assessed pain management by 231 physicians using an online clinical vignette describing a consultation for acute low back pain in a female or male patient. The vignette was followed by a questionnaire that assessed physicians' management decisions and their gender stereotypes.

METHODS

We created an online clinical vignette presenting a patient with acute low back pain and assessed the influence of a patient's gender on pain management. We investigated gender-related stereotyping regarding pain care by emergency physicians using the Gender Role Expectation of Pain questionnaire.

RESULTS

Both male and female physicians tended to consider that a typical man was more sensitive to pain, had less pain endurance, and was more willing to report pain than a typical woman. These stereotypes did not translate into significant differences in pain management between men and women. However, women tended to be referred less often for imaging examinations than men and were also prescribed lower doses of ibuprofen and opioids. The physician's gender had a modest influence on management decisions, female physicians being more likely to prescribe ancillary examinations.

CONCLUSION

We observed gender stereotypes among physicians. Our findings support the hypothesis that social characteristics attributed to men and women influence pain management. Prospective clinical studies are needed to provide a deeper understanding of gender stereotypes and their impact on clinical management.

Age and Gender, but Not Pain are Associated with Pressure Pain Thresholds in Patients with Temporomandibular Disorders: A Cross-Sectional Study

Purpose

This study aims to explore the association of pressure pain thresholds (PPTs) with age, gender, and pain in patients with temporomandibular disorders (TMD).

Patients and Methods

A total of 301 TMD patients (248 female and 53 male) were recruited and classified into the high and low age groups according to their median age of 26 years. Patients' demographics, pain-related variables, TMD-related variables, and PPTs of both left and right temporomandibular joints (TMJs), masseter, and temporalis were collected.

Results

Pain duration and visual analog scale of pain (VAS) showed no significant correlations with PPTs (P>0.05). Multiple linear regression analysis revealed a significant positive association of PPTs of all six sites with males (β=0.41-0.72 kg·cm-2, 95% CI (0.19-0.38, 0.74-0.99), P<0.001), as well as with the high age group [β=0.28-0.36 kg·cm-2, 95% CI (0.07-0.20, 0.47-0.53), P<0.020]. Furthermore, PPTs of the left TMJ showed a significant negative association with left pain-related TMD (PT) [β=-0.21 kg·cm-2, 95% CI (-0.38, -0.04), P=0.026], but PPTs of the remaining sites did not show a significant association with PT (P>0.05). Stratified analysis showed that PPTs in females were associated with the high age group [β=0.25-0.37 kg·cm-2, 95% CI (0.04-0.20, 0.45-0.56), P<0.020] and that PPT of the left TMJ was associated with left PT [β=-0.21 kg·cm-2, 95% CI (-0.39, -0.03), P=0.043]. The remaining PPTs did not show a significant association with PT (P>0.05). In males, PPTs did not show significant correlations with age, PT and VAS (P>0.05).

Conclusion

PPTs in the orofacial region are associated with gender and age in TMD patients. Pain duration and intensity show no significant correlations with PPTs in TMD patients. Researchers and dentists should take age and gender into account when using PPTs as auxiliary diagnostic indicators for PT.

Results of Anorectal Physiological Testing in Patients with Limited English Proficiency

BACKGROUND

Patients with limited English proficiency (LEP) experience barriers to healthcare. These include language barriers and difficulty accessing medical subspecialties. Consequently, patients with LEP may be underrepresented, and may be more likely to have abnormal results, among individuals referred for anorectal testing.

AIMS

To explore whether differences exist in the results of high-resolution anorectal manometry (HRM), rectal sensory testing (RST), and balloon expulsion testing (BET) between patients with LEP and English proficiency (EP).

METHODS

The electronic health records at Mayo Clinic, Rochester were used to identify constipated patients without organic anorectal disease who had undergone anorectal testing in 2018, 2019, and 2020. The language spoken by the patients was determined. HRM, RST, and BET results were compared. Nominal logistic regression explored the influence of age, gender, test operator, and LEP on the likelihood of abnormal findings.

KEY RESULTS

Among 3298 patients (80% female, mean age ± standard deviation 46 ± 16 years), 67 (2%) had LEP. HRM measurements were similar in LEP and EP patients. However, LEP patients were more likely to have abnormal BET and RST. Logistic regression revealed that age (older than 50 years), gender, test operator, and LEP influenced the results of BET and RST, with LEP having the strongest influence.

CONCLUSIONS

Results of anorectal testing in constipated patients differ between LEP and EP patients. This is likely to represent a difference in disease prevalence between these groups, for example, due to referral bias, rather than a difference in physiology or a language barrier.

Migraine in university students: A systematic review and meta-analysis

BACKGROUND

Migraine is a complex, neurobiological disorder usually presenting as a unilateral, moderate to severe headache accompanied by sensory disturbances. Migraine prevalence has risen globally, affecting 14% of individuals and 16% of students and carries many negative impacts in both cohorts. With no recent meta-analysis of global migraine prevalence or associated factors in students, this systematic review and meta-analysis were conducted.

DATABASES AND DATA TREATMENT

The review was registered with PROSPERO (CRD42020167927). Electronic databases (n = 12) were searched for cross-sectional studies (1988 to August 2021, IHS criteria). Ninety-two articles were meta-analysed and 103 were narratively reviewed. The risk of bias was assessed using an established tool.

RESULTS

The risk of bias ranged from low to moderate. Migraine pooled prevalence (R-Studio) was demonstrated at 19% (95% CI, 16%-22%, p < 0.001, I^2 98%): females 23% (95% CI, 19%-27%, p < 0.001), males 12% (95% CI, 9%-15%, p < 0.001). Gender (p < 0.0001), geographical region (p = 0.01), migraine types (p = 0.0002) and prevalence timeframes (p = 0.02) may be influencing the substantial heterogeneity. Migraine triggers were primarily behavioural and environmental and treatments were predominantly pharmaceutical. Impacts ranged from academic performance impairment to psychological co-morbidities.

CONCLUSIONS

This study offers the most comprehensive overview of migraine prevalence and associated factors in university students. Migraine prevalence in university students has increased and has many negative effects. Enhancing migraine recognition and management at university may have positive implications for an improved educational experience, as well as for the burden migraine currently incurs, both in university and beyond.

SIGNIFICANCE

This global systematic review and meta-analysis of 92 studies and narrative review of 103 studies provide the most comprehensive synthesis to date of migraine prevalence and associated factors in university students. Pooled prevalence has increased to 19%. The significant heterogeneity demonstrated is influenced by gender, geographical region, migraine type and prevalence timeframes. Students manage migraines primarily with pharmaceuticals. Further studies conducted in low and middle-income countries, following headache protocols and reporting frequency of treatment-seeking and medication usage are warranted.

Are people good prognosticators of their own pain? An exploration of the relationship between sex-specific pain beliefs and clinical pain evaluation

BACKGROUND

Under-explored to date are the interacting influences of patient sex on multi-modal evaluation techniques that tap different domains of the pain experience.

OBJECTIVES

The primary aim of Study 1 was to explore the accuracy of sex-specific personal pain beliefs in relation to quantitative pain indicators within sexes, and the secondary objective was to compare the accuracy of sex-specific personal pain beliefs in relation to quantitative pain indicators between sexes. The primary objective of Study 2 was to explore the accuracy of sex-specific personal pain beliefs and self-rated pain severity within sexes, and the secondary objective was to compare sex-specific personal pain beliefs and pain severity ratings between sexes.

METHODS

A cross-sectional analysis on two datasets was performed (Study 1, n = 50; Study 2, n = 111). For both studies, independent samples t-tests were used to identify differences in clinical pain evaluations based on sex-specific pain beliefs. Receiver Operating Characteristic (ROC) curves were used to compare the predictive accuracy of males and females clinical pain evaluations based on their ability to handle pain.

RESULTS

There were no statistically significant differences in clinical pain evaluations based on self-rated pain beliefs in either study. In Study 2, males were descriptively more accurate predictors of their clinical pain evaluations than were females, though none of the between sex comparisons were statistically significant.

CONCLUSION

This work highlights the importance of considering all available clinical pain evaluations as one technique is unlikely to represent the patients pain experience.

Pain Control Disparities in Acute Pancreatitis

Background and objective

Patient treatments and outcomes have historically differed based on age, sex, race/ethnicity, and social factors, and there is a growing awareness that such disparities still exist. While prior studies have found that patients belonging to minority groups have their pain undertreated, few studies have evaluated pain control based on age, sex, body mass index (BMI), or presence of a substance use disorder (SUD). The studies that do exist have inconsistent results. This study aimed to evaluate pain control in patients admitted to a Denver academic safety net hospital for acute pancreatitis. Pancreatitis is an inherently painful condition involving pancreatic inflammation and for which adequate pain control is a cornerstone of treatment; this makes it an ideal disease state for an exploratory analysis into the experience of pain within different patient groups.

Methods

This was a retrospective cohort study of patients treated at the Denver Health Medical Center from January 1, 2017, through December 31, 2019, for acute pancreatitis; 659 patients met the inclusion criteria and were included in the study. Pain control during the first 24 hours of hospital admission was analyzed by comparing controlled vs. uncontrolled reports of pain and mean pain scores. Patients were stratified by age, sex, self-reported race/ethnicity, BMI, and presence of SUD at the time of admission. Achievement of "controlled pain," as defined by a pain score below the patient’s stated functional pain goal, was then analyzed. Chi-squared analysis was employed to look into differences within and between groups. Additionally, a t-test was used to compare mean pain scores between groups with controlled and uncontrolled pain.

Results

A statistically significant difference in pain control was found when stratified by age or the presence of SUD (p<0.001). Within these groups, 39% of those aged 18-40 years achieved pain control, compared with 49% of those aged 41-64 years and 66% of those aged 65 years and older. Among those with active SUD, only 41% were able to achieve pain control compared with 58% of those without SUD. Among those who achieved pain control, the average mean pain score was 5, which decreased to 4 within 24 hours. Among those who did not achieve pain control, the average mean pain score was 7, which remained at 7 at 24 hours (p<0.001).

Conclusions

We did not find significant differences in the ability to achieve tolerable pain control based on sex or BMI. We were unable to appropriately analyze differences based on race/ethnicity due to an inability to differentiate between White Hispanic and White non-Hispanic populations within Epic. However, we did find significantly poorer pain control in younger patients and those with an active SUD.

Can Intra-Oral Qualitative Sensory Testing Foretell Postoperative Dental Pain? A Preliminary Report

Pain prevention and management is one of the primary goals of dental care. Postoperative dental pain (PDP) following caries removal and performance of a restorative dental treatment is a common clinical phenomenon, often causing significant discomfort to dental patients. In the present study, a psychophysical non-invasive method, qualitative sensory testing (QualST), was used in an attempt to foretell PDP following dental restorative procedures. Forty-two dental patients underwent an intra-oral cold QualST four times: immediately prior to a restorative dental procedure and at a follow-up meeting 1−3 weeks later, on the treated and on the contralateral oral sides. The QualST measures included subjects’ evaluation of the magnitude of pain and cold sensations experienced (on visual analogue scales) and the duration of the cold sensation (in seconds). Additional measures included age, gender, level of dental anxiety, jaw treated, and type of dental restoration performed (Class I or Class V). Subjects’ PDP was assessed through the phone using numeric rating scales 24, 48, and 72 h postoperatively. The highest level of PDP experienced by subjects occurred 24 h postoperatively (ANOVA with repeated measures). Of the study variables, the QualST pain sensation (B = 0.645, p < 0.001), duration of the cold sensation (B = 0.042, p < 0.05), and an interaction between gender and dental anxiety (B = 0.136, p < 0.05) emerged as possible predictors of the highest PDP experienced by subjects (stepwise regression). The results suggest that subjects’ reaction to an intra-oral cold stimulation of the oral mucosa can serve as a potential tool to foretell postoperative dental pain following restorative dental procedures.

Over-rating pain is overrated: A fundamental self-other bias in pain reporting behavior

Wide-spread cultural beliefs influence personal experiences and clinical treatment of pain, yet are often unexamined and unchallenged in the pain literature. The common cultural belief that people generally over-report or exaggerate pain is familiar, reflected in discordant patient-provider pain assessments, and compounded in the context of disparities in pain treatment. However, no studies have directly measured the prevalence of this belief among the general population, nor challenged the validity of this assumption by assessing normative pain reporting in clinical settings. Results of an initial and replication study suggest that reporting pain accurately "as-is" is the norm, yet most people still believe that others normatively over-report pain. We refer to the phenomenon by which most people report their pain as they experience it while paradoxically believing that others over-report their pain as the fundamental pain bias, and suggest this false perception may contribute to larger scale pain stigma and poor outcomes for people in pain. We also identify counter-stereotypical patterns of pain reporting among groups (i.e., women, Latinx Americans) that face more disparate care. Results reinforce the need for respecting patient pain reports, and suggest that distrust surrounding others' pain experiences is prevalent in society.

Determinants of long-term opioid prescribing in an urban population- a cross sectional study

BACKGROUND

Opioid prescribing has more than doubled in the UK between 1998 and 2016. Potential adverse health implications include dependency, falls and increased health expenditure.

AIM

To describe the predictors of long-term opioid prescribing (LTOP), (≥3 opioid prescriptions in a 90-day period).

DESIGN AND SETTING

A retrospective cross-sectional study in 41 General Practices in South London.

METHOD

Multi-level multivariable logistic regression to investigate the determinants of LTOP.

RESULTS

2,679 (0.8%) out of 320,639 registered patients ≥18 years were identified as having LTOP. Patients Were most likely to have LTOP, if: they had ≥5 long term conditions (LTCs) (adjusted odds ratio [AOR] 36.5, 95% confidence interval [CI] 30.4-43.8) or 2-4 LTCs (AOR 13.8, CI 11.9-16.1), in comparison to no LTCs, ≥75 years compared to 18-24 years (AOR 12.31, CI 7.1-21.5), smokers compared to non-smokers (AOR 2.2, CI 2.0-2.5), females compared to males (AOR 1.9, CI 1.7-2.0) and in the most deprived deprivation quintile (AOR 1.6, CI 1.4-1.8) compared to the least deprived. In a separate model examining individual long-term conditions (LTCs), the strongest associations for LTOP were noted for sickle cell disease (SCD) (AOR 18.4, CI 12.8-26.4), osteoarthritis (AOR 3.0, CI 2.8-3.3), rheumatoid arthritis (AOR 2.8, CI 2.2-3.4), depression (AOR 2.6, CI 2.3-2.8) and multiple sclerosis (OR 2.5, CI 1.4-4.4).

CONCLUSION

LTOP was significantly higher in those aged ≥75 years, with multi-morbidity or specific LTCs: sickle cell disease, osteoarthritis, rheumatoid arthritis, depression, and multiple sclerosis. These characteristics may enable the design of targeted interventions to reduce LTOP.

Translation and validation of modified dental anxiety scale based on adult Taiwan population

Background

Dental anxiety is associated with negative experiences of dental treatment and dental-visiting behavior. The Modified Dental Anxiety Scale (MDAS) is widely used for assessing dental anxiety. The study aims to establish the psychometric properties of a Chinese version of the MDAS based on the Taiwan sample (i.e., T-MDAS).

Methods

The T-MDAS and dental-visiting behavior and experience were assessed for 402 adult subjects recruited from community and clinical sites. The following psychometric properties were assessed: (a) internal consistency, (b) temporal stability, (c) criterion-related validity (i.e., the association with the score of Index of Dental Anxiety and Fear, IDAF-4C), (d) discrimination validity (i.e., the difference in scores between the subjects with and without a habit of a regular dental visit, and (e) the construct validity from a confirmatory factor analysis (CFA). Results. The T-MDAS showed good internal consistency (Cronbach’s α = 0.88) and temporal stability (ρ = 0.69, p < 0.001). The score was significantly correlated with the score of the IDAF-4C (ρ = 0.76, p < 0.001) and differed between subjects who regularly visited a dentist or not, supporting good criterion-related validity and discrimination validity. Results from CFA supports good construct validity. Furthermore, higher dental anxiety was related to the lack of a regular dental visit, feeling pain during treatment, and feeling insufficient skills and empathy of dentists. A higher proportion of high-dental anxiety subjects in female subjects (8.5%), compared to male subjects (5.0%), was noted.

Conclusions

The T-MDAS is a valid tool for assessing adult dental anxiety. The score is highly associated with dental-visiting behavior and experience of dental patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-02017-w.

"Big girls don't cry": the effect of the experimenter's sex and pain catastrophising on pain

OBJECTIVES

The expression of pain in males and females involves complex socio-psychological mechanisms. Males may report lower pain to a female experimenter to appear strong, whereas females may report higher pain to a male experimenter to appear weak and to seek protection. However, evidence to support these stereotypes is inconclusive. Individuals who catastrophise about pain rate higher pain than those who do not. How pain catastrophising interacts with the effect of the experimenter's sex on pain reports is yet to be explored. Thus, the aim of this study was to determine whether pain catastrophising moderated the effect of the experimenter's sex on pain reports in healthy males and females.

METHODS

Participants (n=60, 30 males) were assigned to one of four experimental conditions: males tested by male experimenters, males tested by female experimenters, females tested by male experimenters, and females tested by female experimenters. Participants completed the Pain Catastrophising Scale, and then sensitivity to heat and to blunt (pressure-pain threshold) and sharp stimuli was assessed on both forearms, and to high frequency electrical stimulation (HFS) administered to one forearm.

RESULTS

Females reported lower pressure-pain thresholds than males irrespective of the experimenters' sex. Females reported lower sharpness ratings to male than female experimenters only when the test stimuli were moderately or intensely sharp. Higher pain catastrophising scores were associated with higher sharpness ratings in females but not males. Additionally, higher pain catastrophising scores were associated with greater temporal summation of pain to HFS, and with lower pressure-pain thresholds in females who were tested by male experimenters.

CONCLUSIONS

These findings indicate that the experimenters' sex and the participant's pain catastrophising score influence pain reports, particularly in females. Awareness of these psychosocial factors is important in order to interpret pain responses in a meaningful way, especially when females are tested by male experimenters. A greater awareness of sex/gender role biases and their potential interaction with pain catastrophising may help researchers and clinicians to interpret pain reports in meaningful ways. In turn, this may help to improve delivery of treatments for patients with chronic pain.

Association of temporomandibular disorders with pain sensitivity: A cohort study

BACKGROUND

Pain related to temporomandibular disorders (TMD) can be linked with multiple site pain (MSP), and may associate with increased pain sensitivity, more frequently among women than men. The aim of the study was to examine the associations of pressure pain threshold (PPT) and tolerance (PPTo) with TMD and associated MSP in the Northern Finland Birth Cohort 1966 (NFBC1966) study.

METHODS

Altogether 1961 NFBC1966 subjects attended clinical medical and dental examination at the Institute of Dentistry, University of Oulu in 2012-2013. Clinical examinations were carried out using a modified Diagnostic Criteria for TMD protocol (DC/TMD). MSP was defined based on questions regarding body pain sites. Additionally, PPT and PPTo were assessed using algometer measurements. Mann-Whitney U-test and Tobit regression models were used to analyse associations between TMD sub-diagnoses, MSP, PPT and PPTo, stratified by sex. Further models were adjusted with anxiety and depressive symptoms, which were assessed using Hopkins Symptom Checklist-25 (HSCL-25) and two-way interaction terms.

RESULTS

Among females, lower PPT and PPTo were associated with myalgia and arthralgia. Among males, lower PPT and PPTo were associated with MSP-linked TMD. Tobit regression analysis showed significantly lower PPT and PPTo values in the myalgia and arthralgia subgroups among female TMD subjects. Among females, disc displacement with reduction had an inverse association with PPT and PPTo. Among males, lower PPTo was associated with degenerative joint disease and MSP-linked TMD.

CONCLUSIONS

The pain regulatory mechanisms behind TMD act differently between the genders as local TMD among females and MSP-linked TMD among males were associated with pain sensitivity.

SIGNIFICANCE

The study shows that there are differences in the associations of painful TMD with pressure pain tolerance, pressure pain sensitivity and MSP between male and female subjects.

Understanding Contextual Factors Effects and Their Implications for Italian Physiotherapists: Findings from a National Cross-Sectional Study

An online cross-sectional survey was conducted using Google Docs software. The aim was to understand the management of contextual factors and to identify which are most relevant and which clinicians underestimate. A total of 1250 physiotherapists were chosen from the database of the Manual Therapists group mailing list (GTM-IFOMPT MO) from July to August 2020. A total of 699 responses were received that were considered valid (56%). Participants (40.83%) identified contextual factors (CFs) as "any element, even involuntary, with which the patient interacts during treatment". Physiotherapists individually chose the representation of CF with the "therapeutic relationship" (82.9%), followed by "therapeutic setting" (75.8%). This choice differed between participants belonging to different age groups. Participants favor communication strategies (76.93%). More than half (57.88%) pay attention to patient involvement during the course of care; and in response to the patients' doubts about the use of treatments with limited scientific efficacy, they suggest different medical treatments. The patient's previous clinical experience is not considered significant and does not influence the choice of treatment. Subsequently, however, the participants reported that they stimulate the patients' positive expectations of the success of the clinical outcome (45.27%). Knowledge of contextual factors in physiotherapy appears limited and very heterogeneous. Future research could increase the focus on professional development.

Exploring the Domains of Gender as Measured by a New Gender, Pain and Expectations Scale

Background: While sex- or gender-based differences in pain expression have been documented, exploration of traditionally genderized traits on pain has been hampered by the lack of strong measurement tools. This study evaluated the structural validity of a 16-item "Gender personality traits" subscale of a recently developed Gender, Pain and Expectations Scale (GPES). Methods: Data were drawn from an existing database of 248 participants (65.7% female). Maximum likelihood-based confirmatory factor analysis was carried out while considering the conceptual meaningfulness of subscales to evaluate the factor structure identified by these traits. Construct validity was explored using a priori hypotheses regarding anticipated mean differences in scores between biological male and female participants. Results: A meaningful factor structure could not be defined with all 16 items. Through conceptual and statistical triangulation a three-factor structure informed by 10 items was identified that satisfied acceptable fit criteria. The factors were termed "Emotive," "Relationship-Oriented," and "Goal-Oriented." Evidence of construct validity was supported through significant sex-based differences (p ≤ 0.02) in the expected directions for all three subscales. Conclusions: Review of the items in the three factors led the researchers to endorse a move away from naming these "masculine" and "feminine," rather focusing on the nature of the traits: "Relationship-oriented," "Emotive," and "Goal-oriented." Implications for researchers conducting sex/gender-based pain research are discussed. Clinical Trial Registration number: NCT02711085.

Physical activity and cold pain tolerance in the general population

BACKGROUND

The relationship between habitual physical activity (PA) and experimental pain tolerance has been investigated in small samples of young, healthy and/or single-sex volunteers. We used a large, population-based sample to assess this relationship in men and women with and without chronic pain.

METHODS

We used data from the sixth and seventh Tromsø Study surveys (2007-2008; 2015-2016), with assessed pain tolerance of participants with the cold pressor test (CPT: dominant hand in circulating cold water at 3°C, maximum test time 106 s), and self-reported total amount of habitual PA in leisure time (n = 19,087), exercise frequency (n = 19,388), exercise intensity (n = 18,393) and exercise duration (n = 18,343). A sub-sample had PA measured by accelerometers (n = 4,922). We used Cox regression to compare CPT tolerance times between self-reported PA levels. For accelerometer-measured PA, we estimated hazard ratios for average daily activity counts, and for average daily minutes of moderate-to-vigorous PA done in bouts lasting 10 min or more. Models were tested for PA-sex, and PA-chronic pain and PA-moderate-to-severe chronic pain interactions.

RESULTS

Leisure-time PA, exercise intensity and exercise duration were positively associated with CPT tolerance (p < .001; p = .011; p < .001). More PA was associated with higher CPT tolerance. At high levels of leisure-time PA and exercise intensity, men had a significantly higher CPT tolerance than women. Accelerometer-measured PA was not associated with CPT tolerance.

CONCLUSIONS

This study is one of the first to show that higher self-reported habitual PA was connected to higher experimental pain tolerance in a population-based sample, especially for men. This was not found for accelerometer-measured PA.

SIGNIFICANCE

This study finds that higher level of self-reported leisure-time physical activity is associated with increased cold pressor pain tolerance in a large population-based sample. Though present in both sexes, the association is strongest among men. Despite the robust dose-response relationship between pain tolerance and self-reported activity level, no such relationship was found for accelerometer-measured activity, reflecting a possible discrepancy in the aspect of physical activity measured. Though the study design does not permit causal conclusions, the findings suggest that increasing physical activity may increase pain tolerance in the general population.

Dysfunctional pain perception and modulation among torture survivors: The role of pain personification

OBJECTIVE

Individuals exposed to trauma, especially those who develop posttraumatic stress disorder (PTSD), are at a higher risk of suffering from chronic pain as well as altered pain perception and modulation. However, the underlying mechanisms of these processes are yet to be established. Recent findings have indicated that trauma survivors tend to personify chronic pain that is developed after the exposure, in a way that resonates with the traumatic experience. The aim of this study was to test whether pain personification plays a significant role in explaining the long-term links between trauma, PTSD and pain.

METHODS

This study is part of a large-scale longitudinal study on ex-prisoners of war (ex-POWs) from the 1973 Yom-Kippur war, who were followed over 35 years after the war. Fifty-nine ex-POWs who were exposed to torture and 44 matched combatants were assessed for PTSD at 18, 30, and 35 post-war. Quantitative somatosensory testing of heat-pain threshold, pain tolerance, conditioned pain modulation (CPM), and temporal summation of pain (TSP), as well as torturing personification, were assessed at 35 years after the war.

RESULTS

Sequential mediation analyses revealed that the associations between torture and heat pain threshold, as well as pain tolerance were mediated by PTSD at several time-points (-1.43<indirect effect < 1.47). Torturing personification significantly mediated the associations between torture, PTSD, CPM and TSP (-0.16 < indirect effect).

CONCLUSIONS

These findings point to the effect of trauma on the subjective orientation towards bodily signals as a key factor in dysfunctional pain modulation.

Pain thresholds and intensities of CRPS type I and neuropathic pain in respect to sex

BACKGROUND AND AIMS

Healthy women have generally been found to have increased experimental pain perception and chronic pain has a higher prevalence in female as compared to male patients. However, no study has investigated whether pain intensity and pain perception thresholds are distinct or similar between sexes within various chronic pain entities. We investigated whether average pain intensities and pain thresholds assessed using quantitative sensory testing (QST) differed between women and men suffering from three distinct chronic pain conditions: Complex Regional Pain Syndrome (CRPS type I), peripheral nerve injury (PNI) or polyneuropathy (PNP), as compared to paired healthy volunteers.

METHODS

QST data of 1,252 patients (669 female, 583 male) with PNI (n = 342), PNP (n = 571) or CRPS (n = 339), and average pain intensity reports from previously published studies were included. Absolute and z-values (adjusted for age and body region) of cold, heat, pressure (PPT) and pinprick pain thresholds were compared in generalized linear models with aetiology, duration of underlying pain disease and average pain intensity as fixed effects.

RESULTS

Average pain intensity during the past four weeks did not differ between women and men, in both mean and range. In women absolute pain thresholds for cold, heat and pinprick were lower than in males across all diagnoses (p < .05). However, after z-transformation these differences disappeared except for PPT in CRPS (p = .001).

DISCUSSION

Pain thresholds in patients show only minor sex differences. However, these differences mimic those observed in healthy subjects and do not seem to be linked to specific pathophysiological processes.

SIGNIFICANCE

Female healthy participants and female patients with neuropathic pain conditions or CRPS I report lower pain thresholds compared to males, but pain intensity is similar and there is no sex difference in the extent to which the thresholds are altered in neuropathic pain or CRPS. Thus, the sex differences observed in various chronic pain conditions mimic those obtained in healthy participants, indicating that these differences are not linked to specific pathophysiological processes and are of minor clinical relevance.

The impact of chronic widespread pain on health status and long-term health predictors: a general population cohort study

Background

Chronic widespread pain (CWP) has a negative impact on health status, but results have varied regarding gender-related differences and reported health status. The aim was to study the impact of CWP on health status in women and men aged 35–54 years in a sample of the general population. The aim was further to investigate lifestyle-related predictors of better health status in those with CWP in a 12- and 21-year perspective.

Method

A general population cohort study including 975 participants aged 35–54 years, with a 12- and 21-year follow-up. CWP was measured with a pain mannequin, and the questionnaire included questions on lifestyles factors with SF-36 for measurement of health status. Differences in health status were analysed with independent samples t-test and health predictors with logistic regression analysis.

Results

The prevalence of CWP was higher in women at all time points, but health status was reduced in both women and men with CWP (p < 0.001) with no gender differences of clinical relevance. At the 12-year follow-up, a higher proportion of women than men had developed CWP (OR 2.04; CI 1.27–3.26), and at the 21-year follow-up, a higher proportion of men had recovered from CWP (OR 3.79; CI 1.00–14.33). In those reporting CWP at baseline, a better SF-36 health status (Physical Functioning, Vitality or Mental Health) at the 12-year follow-up was predicted by male gender, having personal support, being a former smoker, and having no sleeping problems. In the 21-year follow-up, predictors of better health were male gender, a weekly intake of alcohol, and having no sleeping problems.

Conclusion

Women and men with CWP have the same worsening of health status, but men recover from CWP to a greater extent in the long-term. Being male, having social support, being a former smoker, and having no sleeping problems were associated with better health status in those with CWP.

Sociodemographic and Environmental Factors are Associated with Adolescents' Pain and Longitudinal Health Outcomes

Research in adult populations indicates that several sociodemographic and environmental variables increase risk for pain and poor outcomes. There is little research exploring the impact of household income, health insurance coverage, barriers to health care, neighborhood and school safety, violence experienced, and neighborhood isolation on pediatric chronic pain. Data from the Add Health Study, a longitudinal examination of a nationally-representative adolescent sample were analyzed. The relationships between demographic variables, risk factors, chronic pain, and long-term health outcomes were examined. Adolescents with chronic pain had lower income, more health care barriers, greater safety concerns, and experienced more violence compared to those without pain. In a model together, female sex, White race/ethnicity, and greater health care barriers, safety concerns, and violence exposure conferred significant risk for chronic pain. Additional analyses revealed nuances in the strength of risk factors between racial/ethnic groups. Systemic health care barriers were significantly associated with chronic pain and may delay symptom alleviation and return to functioning. Considering access to care is necessary in prevention efforts. Among adolescents with chronic pain, greater safety concerns predicted poor mental health outcomes, particularly for White females. The cumulative stress of environmental concerns, such as safety, and managing chronic pain may worsen functioning. PERSPECTIVE: Adolescents with chronic pain had lower income, and more health care barriers, safety concerns, and violence exposure compared to those without chronic pain. Access to care is a significant problem in youth with chronic pain. The relationships between race/ethnicity, risk factors, and health outcomes are complex and require additional research.

Exploring the role of gender and gendered pain expectation in physiotherapy students

Introduction: Gender and gender role pain expectations may influence how health care providers interact with and manage their patients' symptoms. Purpose: The purpose of this study was to describe gendered traits and gender role pain expectations among physical therapy students. Method: A survey assessing gendered traits and gender role expectations in relation to pain was completed by a sample of 171 physical therapy students (120 women, 51 men). Data were analyzed using descriptive statistics and differences between men and women were tested with chi-square or Kruskal-Wallis. Results: Men and women in physical therapy training were not different on 13 out of 16 of the gendered traits. The exceptions were that men rated themselves as more "decisive" compared to women (mean rank = 103.8 vs. mean rank = 78.4, P = 0.001) and women rated themselves as more "emotional" (mean rank = 91.95 vs. mean rank = 72.01, P = 0.009) and more "nurturing" (mean rank = 90.89 vs. mean rank = 72.91, P = 0.020). No significant differences were found in terms of gendered expectations of pain sensitivity, endurance, or in terms of personal experience of pain between the men and women in the sample. However, the majority (75%) of participants reported that women were more willing to report pain compared to men. Finally, both groups rated themselves as no different in handling pain compared to a typical man or woman. Conclusion: In conclusion, men and women in training to be physical therapists demonstrate similar gendered trait profiles and little gender bias in relation to pain expectations.

Gender aspects of the pain syndrome

In recent years, the subject of sex differences in the pain experience attracts a growing interest. The epidemiological and clinical data indicate that women have increased risk of chronic pain, and according to some sources, even experience more intense pain. The hypothetical biological mechanisms underlying sex differences in pain perception consist in the modulating effects produced by sex hormones in relation to the neural substrate. This is confirmed by data on the distribution of gonadal hormones and their receptors in the areas of the peripheral and central nervous system that provide nociceptive transmission. The complexity of the estradiol and progesterone effects on pain sensitivity lies in the fact that, according to various data, both have pre-nociceptive and antinociceptive effects, and testosterone appears to be more characterized by antinociceptive properties. The lion’s share of researches demonstrates the effect of a clinical pain exacerbation during the menstrual cycle. There is irrefutable information about gender differences in responses to drug and non-drug pain treatment, although the results vary depending on a specific therapy and may depend on pain characteristics. Since the recommended dosage of a medication is often based on an “average” male weigh 70 kg, female patients may be facing the risk of increased therapeutic or adverse effects of a drug. The cause is in a higher average percentage of body fat, a lower mean body weight, which contributes to higher median drug concentrations compared with male patients. At present, the available evidence does not allow adapting the methods of pain syndrome treatment to a gender. However, such innovations are quite possible and desirable in the foreseeable future. Additional studies will be required to clarify the mechanisms that determine sex differences in pain responses in order to provide adequate pain relief, according to the patient’s needs.

Examination of psychological risk factors for chronic pain following cardiac surgery: protocol for a prospective observational study

INTRODUCTION

Approximately 400 000 Americans and 36 000 Canadians undergo cardiac surgery annually, and up to 56% will develop chronic postsurgical pain (CPSP). The primary aim of this study is to explore the association of pain-related beliefs and gender-based pain expectations on the development of CPSP. Secondary goals are to: (A) explore risk factors for poor functional status and patient-level cost of illness from a societal perspective up to 12 months following cardiac surgery; and (B) determine the impact of CPSP on quality-adjusted life years (QALYs) borne by cardiac surgery, in addition to the incremental cost for one additional QALY gained, among those who develop CPSP compared with those who do not.

METHODS AND ANALYSES

In this prospective cohort study, 1250 adults undergoing cardiac surgery, including coronary artery bypass grafting and open-heart procedures, will be recruited over a 3-year period. Putative risk factors for CPSP will be captured prior to surgery, at postoperative day 3 (in hospital) and day 30 (at home). Outcome data will be collected via telephone interview at 6-month and 12-month follow-up. We will employ generalised estimating equations to model the primary (CPSP) and secondary outcomes (function and cost) while adjusting for prespecified model covariates. QALYs will be estimated by converting data from the Short Form-12 (version 2) to a utility score.

ETHICS AND DISSEMINATION

This protocol has been approved by the responsible bodies at each of the hospital sites, and study enrolment began May 2015. We will disseminate our results through CardiacPain.Net, a web-based knowledge dissemination platform, presentation at international conferences and publications in scientific journals.

TRIAL REGISTRATION NUMBER

NCT01842568.

Gender, genetics, and analgesia: understanding the differences in response to pain relief

Genetic variations and gender contribute significantly to the large interpatient variations in opioid-related serious adverse effects and differences in pain relief with other analgesics. Opioids are the most commonly used analgesics to relieve moderate-to-severe postoperative pain. Narrow therapeutic index and unexplained large interpatient variations in opioid-related serious adverse effects and analgesia negatively affect optimal perioperative outcomes. In surgical, experimental, chronic, and neuropathic pain models, females have been reported to have more pain than males. This review focuses on literature evidence of differences in pain relief due to multiple genetic variations and gender of the patient.

Predictors of Cold and Pressure Pain Tolerance in Healthy South African Adults

BACKGROUND

Studies on relationships between sex, ethnicity, and pain have largely emanated from the United States and Europe. We compared cold (CPT) and pressure pain tolerance (PPT) in male and female South Africans of African and European ancestry and assessed whether psychosocial factors (including pain beliefs) predicted differences in pain tolerance.

METHODS

We recruited 106 (62 female) students of African ancestry and 106 (55 female) of European ancestry and subjected them to a cold-pressor test and pressure algometry. Socioeconomic status (SES), pain catastrophizing, depression, anxiety, and pain beliefs were assessed as predictors of pain tolerance.

RESULTS

CPT was lower in students of African compared with European ancestry (for both sexes), and PPT was lower in female than male students (for both ethnicities). Females were very accepting of men expressing pain and males less so. Males of African ancestry were least accepting but still tolerant. Multivariate analysis identified African ancestry, and particularly being a female of African ancestry, as strong predictors of lower CPT. Anxiety was a weak predict or of CPT. Sex was the only strong predictor of PPT on multivariate analysis (PPT females < males), and catastrophizing was a weak predictor. Female sex and African ancestry were strong predictors of acceptance of expression of pain in males. SES was a weak predictor of the Appropriate Pain Behavior Questionnaire-Malescore.

CONCLUSIONS

Despite different cultural and social backgrounds from US and European cohorts, we saw similar patterns of sex and ethnic differences in CPT and PPT in an African cohort. Traditional psychosocial predictors of pain sensitivity predicted variation in the outcome variables but were not strong predictors.

The coexistence of psychiatric and gastrointestinal problems in children with restrictive eating in a nationwide Swedish twin study

BACKGROUND

Restrictive eating problems are rare in children but overrepresented in those with neurodevelopmental problems. Comorbidities decrease wellbeing in affected individuals but research in the area is relatively scarce. This study describes phenotypes, regarding psychiatric and gastrointestinal comorbidities, in children with restrictive eating problems.

METHODS

A parental telephone interview was conducted in 9- or 12-year old twins (n = 19,130) in the Child and Adolescent Twin Study in Sweden. Cases of restrictive eating problems and comorbid problems were established using the Autism, Tics-AD/HD and other Comorbidities inventory, parental reports of comorbidity as well as data from a national patient register. In restrictive eating problem cases, presence of psychiatric and gastrointestinal comorbidity was mapped individually in probands and their co-twin. Two-tailed Mann-Whitney U tests were used to test differences in the mean number of coexisting disorders between boys and girls. Odds ratios were used to compare prevalence figures between individuals with or without restrictive eating problems, and Fisher exact test was used to establish significance.

RESULTS

Prevalence of restrictive eating problems was 0.6% (concordant in 15% monozygotic and 3% of dizygotic twins). The presence of restrictive eating problems drastically increased odds of all psychiatric problems, especially autism spectrum disorder in both sexes (odds ratio = 11.9 in boys, odds ratio = 10.1 in girls), obsessive-compulsive disorder in boys (odds ratio = 11.6) and oppositional defiant disorder in girls (odds ratio = 9.22). Comorbid gastrointestinal problems, such as lactose intolerance (odds ratio = 4.43) and constipation (odds ratio = 2.91), were the most frequent in girls. Boy co-twins to a proband with restrictive eating problems generally had more psychiatric problems than girl co-twins and more girl co-twins had neither somatic nor any psychiatric problems at all.

CONCLUSIONS

In children with restrictive eating problems odds of all coexisting psychiatric problems and gastrointestinal problems are significantly increased. The study shows the importance of considering comorbidities in clinical assessment of children with restrictive eating problems.

Technology-Enabled Remote Monitoring and Self-Management - Vision for Patient Empowerment Following Cardiac and Vascular Surgery: User Testing and Randomized Controlled Trial Protocol

Background

Tens of thousands of cardiac and vascular surgeries (CaVS) are performed on seniors in Canada and the United Kingdom each year to improve survival, relieve disease symptoms, and improve health-related quality of life (HRQL). However, chronic postsurgical pain (CPSP), undetected or delayed detection of hemodynamic compromise, complications, and related poor functional status are major problems for substantial numbers of patients during the recovery process. To tackle this problem, we aim to refine and test the effectiveness of an eHealth-enabled service delivery intervention, TecHnology-Enabled remote monitoring and Self-MAnagemenT—VIsion for patient EmpoWerment following Cardiac and VasculaR surgery (THE SMArTVIEW, CoVeRed), which combines remote monitoring, education, and self-management training to optimize recovery outcomes and experience of seniors undergoing CaVS in Canada and the United Kingdom.

Objective

Our objectives are to (1) refine SMArTVIEW via high-fidelity user testing and (2) examine the effectiveness of SMArTVIEW via a randomized controlled trial (RCT).

Methods

CaVS patients and clinicians will engage in two cycles of focus groups and usability testing at each site; feedback will be elicited about expectations and experience of SMArTVIEW, in context. The data will be used to refine the SMArTVIEW eHealth delivery program. Upon transfer to the surgical ward (ie, post-intensive care unit [ICU]), 256 CaVS patients will be reassessed postoperatively and randomly allocated via an interactive Web randomization system to the intervention group or usual care. The SMArTVIEW intervention will run from surgical ward day 2 until 8 weeks following surgery. Outcome assessments will occur on postoperative day 30; at week 8; and at 3, 6, 9, and 12 months. The primary outcome is worst postop pain intensity upon movement in the previous 24 hours (Brief Pain Inventory-Short Form), averaged across the previous 14 days. Secondary outcomes include a composite of postoperative complications related to hemodynamic compromise—death, myocardial infarction, and nonfatal stroke— all-cause mortality and surgical site infections, functional status (Medical Outcomes Study Short Form-12), depressive symptoms (Geriatric Depression Scale), health service utilization-related costs (health service utilization data from the Institute for Clinical Evaluative Sciences data repository), and patient-level cost of recovery (Ambulatory Home Care Record). A linear mixed model will be used to assess the effects of the intervention on the primary outcome, with an a priori contrast of weekly average worst pain intensity upon movement to evaluate the primary endpoint of pain at 8 weeks postoperation. We will also examine the incremental cost of the intervention compared to usual care using a regression model to estimate the difference in expected health care costs between groups.

Results

Study start-up is underway and usability testing is scheduled to begin in the fall of 2016.

Conclusions

Given our experience, dedicated industry partners, and related RCT infrastructure, we are confident we can make a lasting contribution to improving the care of seniors who undergo CaVS.

Roads Less Traveled: Sexual Dimorphism and Mast Cell Contributions to Migraine Pathology

Migraine is a common, little understood, and debilitating disease. It is much more prominent in women than in men (~2/3 are women) but the reasons for female preponderance are not clear. Migraineurs frequently experience severe comorbidities, such as allergies, depression, irritable bowel syndrome, and others; many of the comorbidities are more common in females. Current treatments for migraine are not gender specific, and rarely are migraine and its comorbidities considered and treated by the same specialist. Thus, migraine treatments represent a huge unmet medical need, which will only be addressed with greater understanding of its underlying pathophysiology. We discuss the current knowledge about sex differences in migraine and its comorbidities, and focus on the potential role of mast cells (MCs) in both. Sex-based differences in pain recognition and drug responses, fluid balance, and the blood–brain barrier are recognized but their impact on migraine is not well studied. Furthermore, MCs are well recognized for their prominent role in allergies but much less is known about their contributions to pain pathways in general and migraine specifically. MC-neuron bidirectional communication uniquely positions these cells as potential initiators and/or perpetuators of pain. MCs can secrete nociceptor sensitizing and activating agents, such as serotonin, prostaglandins, histamine, and proteolytic enzymes that can also activate the pain-mediating transient receptor potential vanilloid channels. MCs express receptors for both estrogen and progesterone that induce degranulation upon binding. Furthermore, environmental estrogens, such as Bisphenol A, activate MCs in preclinical models but their impact on pain pathways or migraine is understudied. We hope that this discussion will encourage scientists and physicians alike to bridge the knowledge gaps linking sex, MCs, and migraine to develop better, more comprehensive treatments for migraine patients.

Attitudes toward Assisted Suicide: Does Family Context Matter?

Little is known about how family-related contextual variables impact attitudes toward assisted suicide. A probability sample (N = 272) responded to a multiple-segment factorial vignette designed to examine the effects of 6 variables-patient sex, age, type of illness, relationship status, parenthood status, and family support-on attitudes toward physician- and family-assisted suicide. Respondents were more likely to support physician-assisted suicide if they heard about an older patient or a patient experiencing physical pain than a younger patient or one suffering from depression, respectively. For family-assisted suicide, respondent support was higher when the patient had physical pain than depression, and when the patient's spouse or friend was supportive of the wish to die than unsupportive. Attitudes about physician and family obligation to inform others were affected by type of illness, relationship status, family support, and respondent education and religiosity. The experience of pain, motivations for family involvement, confidentiality issues, and physicians' biases concerning assisted suicide are discussed.

A cross sectional study between the prevalence of chronic pain and academic pressure in adolescents in China (Shanghai)

Background

The purpose of this study was to investigate the prevalence of four types of chronic pain (headache, abdominal pain, neck and shoulder pain (NSP), and low back pain (LBP)) and to explore the relationship between the prevalence of chronic pain and self-reported academic pressure in high school students in Shanghai, China.

Method

Three thousand students were randomly surveyed on related issues using a questionnaire, and the results were analyzed using a multivariate logistic regression model.

Results

Among the 2849 high school students who completed the questionnaire, the overall prevalence rates of headache, abdominal pain, NSP, and LBP were 30.3, 20.9, 32.8, and 41.1 %, respectively. The students in general experienced a heavy burden of learning, a high level of stress, and sleep deprivation, which were closely related to the four types of chronic pain.

Conclusion

Chronic pain is a common condition in Chinese adolescents and is closely related to self-reported academic pressure.

The Curse of Curves: Sex Differences in the Associations Between Body Shape and Pain Expression

This study examines the associations between objective and subjective measurements and impressions of body shape and cold pressor pain reporting in healthy adults. On the basis of sexual selection theory (SST), we hypothesized that body characteristics that are universally preferred by the opposite sex-specifically, lower waist-to-hip ratios (WHR) in women and higher shoulder-to-hip ratios (SHR) in men-and characteristics (e.g., proportion of body fat in women) that infer attractiveness differently across cultures will correspond to higher experimental pain reporting in women and lower pain reporting in males. A convenience sample of young adults (n = 96, 58 females, 18-24 years; mean age = 19.4) was measured for body mass index (BMI), WHR, SHR, and subjective body impressions (SBI), along with cold pressor pain reporting. The findings showed that BMI was positively associated with WHR and less-positive SBI in both sexes. Consistent with SST, however, only BMI and WHR predicted variability in pain expression in women, whereas only SHR predicted variability in men. Subjective body impressions were positively associated with SHR among males and unrelated to WHR among females, yet only females showed a positive association between SBI and higher pain reporting. The findings suggest that sexually selected physical characteristics (WHR and SHR) and culturally influenced somatic (BMI) and psychological (SBI) indicators of attractiveness correspond with variability in pain reporting, potentially reflecting the general tendency for people to express clusters of sexually selected and culturally influenced traits that may include differential pain perception.

Computer-delivered social norm message increases pain tolerance

BACKGROUND

Few experimental studies have been conducted on social determinants of pain tolerance.

PURPOSE

This study tests a brief, computer-delivered social norm message for increasing pain tolerance.

METHODS

Healthy young adults (N = 260; 44 % Caucasian; 27 % Hispanic) were randomly assigned into a 2 (social norm) × 2 (challenge) cold pressor study, stratified by gender. They received standard instructions or standard instructions plus a message that contained artificially elevated information about typical performance of others.

RESULTS

Those receiving a social norm message displayed significantly higher pain tolerance, F(1, 255) = 26.95, p < .001, η p (2)  = .10 and pain threshold F(1, 244) = 9.81, p = .002, η p (2)  = .04, but comparable pain intensity, p > .05. There were no interactions between condition and gender on any outcome variables, p > .05.

CONCLUSIONS

Social norms can significantly increase pain tolerance, even with a brief verbal message delivered by a video.

Sex differences in pain: a brief review of clinical and experimental findings

Recent years have witnessed substantially increased research regarding sex differences in pain. The expansive body of literature in this area clearly suggests that men and women differ in their responses to pain, with increased pain sensitivity and risk for clinical pain commonly being observed among women. Also, differences in responsivity to pharmacological and non-pharmacological pain interventions have been observed; however, these effects are not always consistent and appear dependent on treatment type and characteristics of both the pain and the provider. Although the specific aetiological basis underlying these sex differences is unknown, it seems inevitable that multiple biological and psychosocial processes are contributing factors. For instance, emerging evidence suggests that genotype and endogenous opioid functioning play a causal role in these disparities, and considerable literature implicates sex hormones as factors influencing pain sensitivity. However, the specific modulatory effect of sex hormones on pain among men and women requires further exploration. Psychosocial processes such as pain coping and early-life exposure to stress may also explain sex differences in pain, in addition to stereotypical gender roles that may contribute to differences in pain expression. Therefore, this review will provide a brief overview of the extant literature examining sex-related differences in clinical and experimental pain, and highlights several biopsychosocial mechanisms implicated in these male-female differences. The future directions of this field of research are discussed with an emphasis aimed towards further elucidation of mechanisms which may inform future efforts to develop sex-specific treatments.

Gender role expectations of pain mediate sex differences in cold pain responses in healthy Libyans

Previous studies found a relationship between response to experimentally-induced pain and scores for the gender role expectations of pain (GREP) questionnaire. Findings were similar in individuals from America, Portugal and Israel suggesting that gender role expectations may be universal. The aim of this study was to translate and validate Arabic GREP using Factor Analysis and to investigate if sex differences to cold-pressor pain in healthy Libyan men and women are mediated through stereotypical social constructs of gender role expectations and/or pain-related anxiety. One hundred fourteen university students (58 women) underwent two cycles of cold pressor pain test to measure pain threshold, tolerance, intensity, and unpleasantness. Participants also completed the Arabic GREP questionnaire and the Pain Anxiety Symptom Scale-Short form (PASS-20). It was found that Libyan men had higher pain thresholds and tolerances than women (mean difference, 95% CI: threshold = 4.69 (s), -0.72 to 10.1, p = 0.005; tolerance = 13.46 (s), 0.5-26.4, p = 0.018). There were significant differences between sexes in 6 out of 12 GREP items (p < 0.004 after Bonferonni adjustment). The results of mediational analysis showed that GREP factors were the mediators of the effects of sex on pain threshold (z = -2.452, p = 0.014 for Self Sensitivity); (z = -2.563, p = 0.01, for Self Endurance) and on pain tolerance (z = -2.538, p = 0.01 for Self Endurance). In conclusion, sex differences in response to pain were mediated by gender role expectations of pain but not pain-related anxiety.

Effects of ethnicity and gender role expectations of pain on experimental pain: a cross-cultural study

BACKGROUND

Gender role expectations of pain (GREP) have been shown to mediate sex differences in experimental pain. Few studies have investigated the role of ethnicity in shaping GREP. The aim of this study was to examine interactions between ethnicity and GREP on experimentally induced pressure and ischaemic pain in Libyan and white British students in their respective countries.

METHODS

Libyan (n = 124) and white British (n = 51) students completed a GREP questionnaire and their response to experimental pain was measured. Blunt pressure pain threshold (PPT) was measured over the 1st interosseous muscle using algometry. Pain intensity and pain unpleasantness (100 mm visual analogue scale) were measured at 1-min intervals during a submaximal effort tourniquet test on the forearm.

RESULTS

Multivariate analysis of variance detected significant effects for Sex and Ethnicity on pain measurements. Men had higher PPTs than women (p < 0.001). Libyans had higher PPTs than white British participants (p < 0.001). There were significant effects for Sex and Ethnicity for pain intensity ratings (p < 0.01) but no significant differences between the sexes in pain unpleasantness (p > 0.05). Libyan participants had higher pain intensity (p < 0.01) and pain unpleasantness (p < 0.05) ratings compared with white British participants. There were effects for Sex and Ethnicity for all GREP dimensions. Libyan participants exhibited stronger stereotypical views in GREP than white British participants (p < 0.001).

CONCLUSIONS

GREP was the mediator of sex but not ethnic differences in pain report, suggesting that gender stereotypical attitudes to pain account for differences in pain expression between men and women.

Inequality in analgesic prescription in Spain. A gender development issue

OBJECTIVES

It is well known that sex differences in analgesic prescription are not merely the logical result of greater prevalence of pain in women, since this therapeutic variability is related to factors such as educational level or social class. This study aims to analyse the relationship between analgesic prescription and gender development in different regions of Spain.

METHODS

Cross-sectional study of sex-differences in analgesic prescription according to the gender development of the regions studied. Analgesic prescription, pain and demographic variables were obtained from the Spanish Health Interview Survey in 2006. Gender development was measured with the Gender Development Index (GDI). A logistic regression analysis was conducted to compare analgesic prescription by sex in regions with a GDI above or below the Spanish average.

RESULTS

Once adjusted by pain, age and social class, women were more likely to be prescribed analgesics than men, odds ratio (OR) = 1.74 (1.59-1.91), as residents in regions with a lower GDI compared with those in region with a higher GDI: ORWomen = 1.26 (1.12-1.42), ORMen = 1.30 (1.13-1.50). Women experiencing pain in regions with a lower GDI were more likely than men to be treated by a general practitioner rather than by a specialist, OR = 1.32 (1.04-1.67), irrespective of age and social class.

CONCLUSIONS

Gender bias may be one of the pathways by which inequalities in analgesic treatment adversely affect women's health. Moreover, research into the adequacy of analgesic treatment and the possible medicalisation of women should consider contextual factors, such as gender development.