An oral glucose tolerance test does not affect cerebral blood flow: role of NOS.

Animal data indicate that insulin triggers a robust nitric oxide synthase (NOS)-mediated dilation in cerebral arteries similar to the peripheral tissue vasodilation observed in healthy adults. Insulin's role in regulating cerebral blood flow (CBF) in humans remains unclear but may be important for understanding the links between insulin resistance, diminished CBF, and poor brain health outcomes. We tested the hypothesis that an oral glucose challenge (oral glucose tolerance test, OGTT), which increases systemic insulin and glucose, would acutely increase CBF in healthy adults due to NOS-mediated vasodilation, and that changes in CBF would be greater in anterior regions where NOS expression or activity may be greater. In a randomized, single-blind approach, 18 young healthy adults (24 ± 5 yr) underwent magnetic resonance imaging (MRI) with a placebo before and after an OGTT (75 g glucose), and 11 of these adults also completed an NG-monomethyl-l-arginine (l-NMMA) visit. Four-dimensional (4-D) flow MRI quantified macrovascular CBF and arterial spin labeling (ASL) quantified microvascular perfusion. Subjects completed baseline imaging with a placebo (or l-NMMA), then consumed an OGTT followed by MRI scans and blood sampling every 10-15 min for 90 min. Contrary to our hypothesis, total CBF (P = 0.17) and global perfusion (P > 0.05) did not change at any time point up to 60 min after the OGTT, and no regional changes were detected. l-NMMA did not mediate any effect of OGTT on CBF. These data suggest that insulin-glucose challenge does not acutely alter CBF in healthy adults.

Reduced basal macrovascular and microvascular cerebral blood flow in young adults with metabolic syndrome: potential mechanisms.

Ninety-million Americans suffer metabolic syndrome (MetSyn), increasing the risk of diabetes and poor brain outcomes, including neuropathology linked to lower cerebral blood flow (CBF), predominantly in anterior regions. We tested the hypothesis that total and regional CBF is lower in MetSyn more so in the anterior brain and explored three potential mechanisms. Thirty-four controls (25 ± 5 yr) and 19 MetSyn (30 ± 9 yr), with no history of cardiovascular disease/medications, underwent four-dimensional flow magnetic resonance imaging (MRI) to quantify macrovascular CBF, whereas arterial spin labeling quantified brain perfusion in a subset (n = 38/53). Contributions of cyclooxygenase (COX; n = 14), nitric oxide synthase (NOS, n = 17), or endothelin receptor A signaling (n = 13) were tested with indomethacin, NG-monomethyl-L-arginine (L-NMMA), and Ambrisentan, respectively. Total CBF was 20 ± 16% lower in MetSyn (725 ± 116 vs. 582 ± 119 mL/min, P < 0.001). Anterior and posterior brain regions were 17 ± 18% and 30 ± 24% lower in MetSyn; reductions were not different between regions (P = 0.112). Global perfusion was 16 ± 14% lower in MetSyn (44 ± 7 vs. 36 ± 5 mL/100 g/min, P = 0.002) and regionally in frontal, occipital, parietal, and temporal lobes (range 15-22%). The decrease in CBF with L-NMMA (P = 0.004) was not different between groups (P = 0.244, n = 14, 3), and Ambrisentan had no effect on either group (P = 0.165, n = 9, 4). Interestingly, indomethacin reduced CBF more in Controls in the anterior brain (P = 0.041), but CBF decrease in posterior was not different between groups (P = 0.151, n = 8, 6). These data indicate that adults with MetSyn exhibit substantially reduced brain perfusion without regional differences. Moreover, this reduction is not due to loss of NOS or gain of ET-1 signaling but rather a loss of COX vasodilation.NEW & NOTEWORTHY We tested the impact of insulin resistance (IR) on resting cerebral blood flow (CBF) in adults with metabolic syndrome (MetSyn). Using MRI and research pharmaceuticals to study the role of NOS, ET-1, or COX signaling, we found that adults with MetSyn exhibit substantially lower CBF that is not explained by changes in NOS or ET-1 signaling. Interestingly, adults with MetSyn show a loss of COX-mediated vasodilation in the anterior but not posterior circulation.

Revisiting patient-related barriers to cancer pain management in the context of the US opioid crisis.

ABSTRACT: Patient fear of addiction is a well-documented barrier to the use of analgesic medications for cancer pain control. Over the past 2 decades in the United States, an "opioid crisis" has arisen, accompanied by risk messages delivered through news outlets, public health education, and patient-provider communication. The purpose of this study was to determine if patient-related barriers to cancer pain management-specifically, fears of addiction-and related pain outcomes (pain severity, pain interference with daily life, and adequacy of pain management) have worsened over the last 20 years. A sample of 157 outpatients with active recurrent or active metastatic cancer completed the Barriers Questionnaire-II (BQ-II) and measures of pain and analgesic use. We identified 7 comparison studies published between 2002 and 2020 that reported patient-related barriers using the BQ-II. Significant linear relationships were found between later year of publication and greater fear of addiction (harmful effect subscale score, B = 0.0350, R2 = 0.0347, F1,637 = 23.19, P < 0.0001) and between year of publication and more pain management barriers overall (total BQ-II score, B = 0.039, R2 = 0.065, F1,923 = 73.79, P < 0.0001). Relationships between BQ-II scores (harmful effect and total) and pain outcomes did not change over time. Despite worsening in patient-related barriers, the proportion of patients with adequate vs inadequate analgesic use did not differ over time. Notably, 40% of participants reported inadequate analgesic use, a statistic that has not improved in 20 years. Additional research is necessary to clarify factors contributing to changing beliefs. Findings indicate a continuing need for clinical and possibly system/policy-level interventions to support adequate cancer pain management.

Randomized controlled trial of a brief cognitive-behavioral strategies intervention for the pain, fatigue, and sleep disturbance symptom cluster in advanced cancer.

OBJECTIVE: Patients receiving treatment for advanced cancer suffer significant symptom burden, including co-occurring pain, fatigue, and sleep disturbance. There is limited evidence for effective interventions targeting this common symptom cluster. METHODS: A randomized controlled trial of a brief cognitive-behavioral strategies (CBS) intervention was conducted. A sample of 164 patients with advanced cancer receiving chemotherapy practiced imagery, relaxation, and distraction exercises or listened to cancer education recordings (attention-control) to manage co-occurring pain, fatigue, and sleep disturbance over a 9-week period. Symptom cluster severity, distress, and interference with daily life were measured at baseline and 3, 6, and 9 weeks. We also evaluated the moderating influence of imaging ability and number of concurrent symptoms, and mediating effects of changes in stress, anxiety, outcome expectancy, and perceived control over symptoms. RESULTS: Compared with the cancer education condition, participants receiving the CBS intervention reported less symptom cluster distress at week 6 (M = 1.82 vs 2.15 on a 0-4 scale, P < .05). No other group differences were statistically significant. The number of concurrent symptoms moderated the intervention effect on symptom cluster interference. Changes in stress, outcome expectancy, and perceived control mediated the extent of intervention effects on symptom outcomes, primarily at weeks 6 and 9. CONCLUSIONS: The brief CBS intervention had limited effects in this trial. However, findings regarding potential mediators affirm hypothesized mechanisms and provide insight into ways to strengthen future interventions to reduce the suffering associated with co-occurring pain, fatigue, and sleep disturbance.

The Role of Inflammation in the Pain, Fatigue, and Sleep Disturbance Symptom Cluster in Advanced Cancer.

CONTEXT: Symptom researchers have proposed a model of inflammatory cytokine activity and dysregulation in cancer to explain co-occurring symptoms including pain, fatigue, and sleep disturbance. OBJECTIVES: We tested the hypothesis that psychological stress accentuates inflammation and that stress and inflammation contribute to one's experience of the pain, fatigue, and sleep disturbance symptom cluster (symptom cluster severity, symptom cluster distress) and its impact (symptom cluster interference with daily life, quality of life). METHODS: We used baseline data from a symptom cluster management trial. Adult participants (N = 158) receiving chemotherapy for advanced cancer reported pain, fatigue, and sleep disturbance on enrollment. Before intervention, participants completed measures of demographics, perceived stress, symptom cluster severity, symptom cluster distress, symptom cluster interference with daily life, and quality of life and provided a blood sample for four inflammatory biomarkers (interleukin-1ß, interleukin-6, tumor necrosis factor-α, and C-reactive protein). RESULTS: Stress was not directly related to any inflammatory biomarker. Stress and tumor necrosis factor-α were positively related to symptom cluster distress, although not symptom cluster severity. Tumor necrosis factor-α was indirectly related to symptom cluster interference with daily life, through its effect on symptom cluster distress. Stress was positively associated with symptom cluster interference with daily life and inversely with quality of life. Stress also had indirect effects on symptom cluster interference with daily life, through its effect on symptom cluster distress. CONCLUSION: The proposed inflammatory model of symptoms was partially supported. Investigators should test interventions that target stress as a contributing factor in co-occurring pain, fatigue, and sleep disturbance and explore other factors that may influence inflammatory biomarker levels within the context of an advanced cancer diagnosis and treatment.

The effectiveness of the Pain Resource Nurse Program to improve pain management in the hospital setting: A cluster randomized controlled trial.

BACKGROUND: The Pain Resource Nurse program is a widely disseminated, evidence-based, nursing staff development program, designed to improve pain management in hospitals. The program has shown promising results, but has never been tested with a rigorous research design. OBJECTIVES: Our objective was to test the effectiveness of the Pain Resource Nurse program. Hypothesized outcomes included improvements in nurses' knowledge, attitudes, and assessment practices, and in patients' participation in decision-making, adequacy of pain management, pain severity, time spent in severe pain, pain interference, and satisfaction. DESIGN: Cluster randomized controlled trial. SETTING: A 650-bed university hospital in Iceland Participants: The sample consisted of a) patients ≥18 years of age, native speaking, hospitalized for at least 24h, alert and able to participate; and b) registered nurses who worked on the participating units. METHODS: Twenty three surgical and medical inpatient units were randomly assigned to the Pain Resource Nurse program (n=12) or to wait list control (n=11). The American Pain Society Outcome Questionnaire and the Knowledge and Attitudes Survey were used to collect data from patients and nurses respectively. Baseline data (T1) for patients were collected simultaneously on all units, followed by data collection from nurses. Then randomization took place, and the Pain Resource Nurse program was instituted. Ten months later, follow up (T2) data were collected, after which the nurses on the control group units received the Pain Resource Nurse program. RESULTS: At baseline, data were collected from 305 of the 396 eligible patients and at follow up from 326 of the 392 eligible patients, a 77% and 83% response rate respectively. At baseline, 232 of 479 eligible nurses responded and at follow-up 176 of the eligible 451 nurses responded, a 49% and 39% response rate, respectively. A nested mixed model analysis of covariance revealed that the intervention was successful in changing pain assessment practices, with pain assessment using standardized measures increasing from 13% to 25% in the intervention group while decreasing from 21% to 16% in the control group. None of the other hypothesized improvements were found. CONCLUSIONS: The Pain Resource Nurse program was successful in improving nurses' use of standardized measures for pain assessment. No effects were found on patient outcomes; pain was both prevalent and severe at both time points. Only minimal improvements were noted in response to this evidence-based staff development program. Changes in pain management practices remain a challenge in clinical settings.

Size and consistency of problem-solving consultation outcomes: an empirical analysis.

In this study, we analyzed extant data to evaluate the variability and magnitude of students' behavior change outcomes (academic, social, and behavioral) produced by consultants through problem-solving consultation with teachers. Research questions were twofold: (a) Do consultants produce consistent and sizeable positive student outcomes across their cases as measured through direct and frequent assessment? and (b) What proportion of variability in student outcomes is attributable to consultants? Analyses of extant data collected from problem-solving consultation outcome studies that used single-case, time-series AB designs with multiple participants were analyzed. Four such studies ultimately met the inclusion criteria for the extant data, comprising 124 consultants who worked with 302 school teachers regarding 453 individual students. Consultants constituted the independent variable, while the primary dependent variable was a descriptive effect size based on student behavior change as measured by (a) curriculum-based measures, (b) permanent products, or (c) direct observations. Primary analyses involved visual and statistical evaluation of effect size magnitude and variability observed within and between consultants and studies. Given the nested nature of the data, multilevel analyses were used to assess consultant effects on student outcomes. Results suggest that consultants consistently produced positive effect sizes on average across their cases, but outcomes varied between consultants. Findings also indicated that consultants, teachers, and the corresponding studies accounted for a significant proportion of variability in student outcomes. This investigation advances the use of multilevel and integrative data analyses to evaluate consultation outcomes and extends research on problem-solving consultation, consultant effects, and meta-analysis of case study AB designs. Practical implications for evaluating consultation service delivery in school settings are also discussed.

Preserved Microvascular Endothelial Function in Young, Obese Adults with Functional Loss of Nitric Oxide Signaling.

Data indicate endothelium-dependent dilation (EDD) may be preserved in the skeletal muscle microcirculation of young, obese adults. Preserved EDD might be mediated by compensatory mechanisms, impeding insight into preclinical vascular dysfunction. We aimed to determine the functional roles of nitric oxide synthase (NOS) and cyclooxygenase (COX) toward EDD in younger obese adults. We first hypothesized EDD would be preserved in young, obese adults. Further, we hypothesized a reduced contribution of NOS in young, obese adults would be replaced by increased COX signaling. Microvascular EDD was assessed with Doppler ultrasound and brachial artery infusion of acetylcholine (ACh) in younger (27 ± 1 year) obese (n = 29) and lean (n = 46) humans. Individual and combined contributions of NOS and COX were examined with intra-arterial infusions of l-NMMA and ketorolac, respectively. Vasodilation was quantified as an increase in forearm vascular conductance (ΔFVC). Arterial endothelial cell biopsies were analyzed for protein expression of endothelial nitric oxide synthase (eNOS). ΔFVC to ACh was similar between groups. After l-NMMA, ΔFVC to ACh was greater in obese adults (p < 0.05). There were no group differences in ΔFVC to ACh with ketorolac. With combined NOS-COX inhibition, ΔFVC was greater in obese adults at the intermediate dose of ACh. Surprisingly, arterial endothelial cell eNOS and phosphorylated eNOS were similar between groups. Younger obese adults exhibit preserved EDD and eNOS expression despite functional dissociation of NOS-mediated vasodilation and similar COX signaling. Compensatory NOS- and COX-independent vasodilatory mechanisms conceal reduced NOS contributions in otherwise healthy obese adults early in life, which may contribute to vascular dysfunction.

Pilot randomized controlled trial of a patient-controlled cognitive-behavioral intervention for the pain, fatigue, and sleep disturbance symptom cluster in cancer.

CONTEXT: Pain, fatigue, and sleep disturbance commonly co-occur in patients receiving treatment for advanced cancer. OBJECTIVES: A pilot randomized controlled trial was conducted to assess initial efficacy of a patient-controlled cognitive-behavioral (CB) intervention for the pain, fatigue, and sleep disturbance symptom cluster. METHODS: Eighty-six patients with advanced lung, prostate, colorectal, or gynecologic cancers receiving treatment at a comprehensive cancer center were stratified by recruitment clinics (chemotherapy and radiation therapy) and randomized to intervention or control groups. Forty-three patients were assigned to receive training in and use of up to 12 relaxation, imagery, or distraction exercises delivered via an MP3 player for two weeks during cancer treatment. Forty-three patients were assigned to a waitlist control condition for the same two week period. Outcomes included symptom cluster severity and overall symptom interference with daily life measured at baseline (Time 1) and two weeks later (Time 2). RESULTS: Eight participants dropped out; 78 completed the study and were analyzed (36 intervention and 42 control subjects). Participants used the CB strategies an average of 13.65 times (SD=6.98). Controlling for baseline symptom cluster severity and other relevant covariates, it was found that the symptom cluster severity at Time 2 was lower in the intervention group (M(Adj)=2.99, SE=0.29) than in the waitlist group (M(Adj)=3.87, SE=0.36), F(1, 65)=3.57, P=0.032. Symptom interference with daily life did not differ between groups. No significant adverse events were noted with the CB intervention. CONCLUSION: Findings suggest that the CB intervention may be an efficacious approach to treating the pain, fatigue, and sleep disturbance symptom cluster. Future research is planned to confirm efficacy and test mediators and moderators of intervention effects.

Mediating processes of two communication interventions for breast cancer patients.

OBJECTIVE: Test whether three mediating processes of Self-Determination Theory are involved in intervention effects on quality of life for breast cancer patients. METHODS: A randomized clinical trial recruited newly diagnosed breast cancer patients for 6 months of (1) Internet training and access, (2) access to an integrated eHealth system for breast cancer (CHESS), (3) a series of phone conversations with a Human Cancer Information Mentor, or (4) both (2) and (3). RESULTS: This paper reports results after the initial 6 weeks of intervention, at which point patients in the combined condition had higher quality of life scores than those in the other three conditions. All three Self-Determination Theory constructs (autonomy, competence, and relatedness) mediated that effect as hypothesized. In addition, the single-intervention groups were superior to the Internet-only group on relatedness, though perhaps this was too soon for that to carry through to quality of life as well. CONCLUSIONS: The SDT constructs do mediate these interventions' effects. PRACTICE IMPLICATIONS: Intervention design can profitably focus on enhancing autonomy, competence and relatedness.

Regarding p rep: comment prompted by Iverson, Wagenmakers, and Lee (2010); Lecoutre, Lecoutre, and Poitevineau (2010); and Maraun and Gabriel (2010).

The sense that replicability is an important aspect of empirical science led Killeen (2005a) to define prep, the probability that a replication will result in an outcome in the same direction as that found in a current experiment. Since then, several authors have praised and criticized prep, culminating in the 3 articles in the current issue of Psychological Methods. In this article, Killeen's prep is reviewed, and the contributions of the current articles are summarized and discussed. An examination of the role of a measure of theoretical support such as prep in the acquisition of knowledge leads me to concur with Senn (2002) that prep is of little epistemological value.

Testing mediation in nursing research: beyond Baron and Kenny.

BACKGROUND: R. M. Baron and D. A. Kenny (1986) defined mediation and described how to perform statistical tests of mediation hypotheses. Their approach to testing mediation has been used extensively in the nursing literature. However, many statisticians have identified problems with the Baron and Kenny approach. PURPOSE: The aim of this paper is to critically evaluate alternative approaches to testing mediation. APPROACH: The Baron and Kenny approach and its shortcomings are briefly reviewed. A critical analysis of 17 alternate methods in three categories is then presented: (a)causal steps, (b) difference in coefficients, and (c) product of coefficients. The evaluation focuses on Type I error rate control, power, ease of computation, and versatility of use. RESULTS: Of the methods that control Type I error rate adequately, the joint significance test of [alpha] and [beta], the asymmetric distribution of products test, and the test of the products using the percentile bootstrap method are the most powerful tests of mediation. Of these three, the joint significance test of [alpha] and [beta] is superior due to its computational ease and versatility of use. DISCUSSION: Knowledge development in nursing will benefit from continued research testing mediation models. Nurse researchers could move beyond the Baron and Kenny approach to utilize more robust tests of mediation.

A population based study of the prevalence of pain in Iceland.

Prevalence estimates of pain differ depending on how it is defined and measured and on the populations studied. It has been estimated that on a given day, as many as 30-44% of the general population experience some kind of pain. Information about the prevalence of pain in Iceland is not available. The aims of this study were to evaluate the prevalence of pain of various origins among the general population of Iceland, to test hypotheses regarding relationships between pain, quality of life (QOL) and demographic variables, to evaluate participants' beliefs about causes of their pain, and to evaluate how those who experience pain manage it. A random sample of 1286 adults was drawn from a national registry holding information about all citizens of Iceland. Data were collected with a postal-survey. Pain was evaluated with the Brief Pain Inventory (BPI), with instructions modified to evaluate pain in the past week as opposed to the past 24 h. Of 1286 invited, 599 (46.6%) participated, of which, 232 had experienced pain in the past week (40.3%). Participants had a mean (SD) age of 44.94 (17.12) years and 56% were women. Those who had pain perceived their health to be worse than those who had not [B = -0.91, SE = 0.15, Wald = 38.75, p = 0.00], but did not differ on other variables. Of 232 individuals reporting pain, 183 (79.6%) or 30.6% of the total sample had experienced pain for more than three months. On a scale from 0 "no pain" to 10 "pain as bad as I can imagine" the mean (SD) pain severity score (composite of four pain severity scores) for the 232 participants reporting pain was 3.21 (1.73) and pain interference with life activities 2.59 (1.98), also on a 0-10 scale. Pain severity predicted pain interference [B = 0.71; F = 126.14; df = 1,206; p = 0.00], which mediated the effects of pain severity on mood and QOL. Between Pain Interference with Life and Positive Affect [B = -0.06; F = 4.53; df = 1,196; p = 0.04], between Pain Interference and Negative Affect [B = 0.15; F = 23.21; df = 1,196; p = 0.00], and between Pain Interference and Global Quality of Life [B = -0.18; F = 29.11; df = 1,196; p = 0.00]. Most frequent causes for pain were strain injuries (n = 79), resulting from work or sports activity, arthritis (n = 39), mechanical problems (e.g. due to birth defects, curvature, slipped discs, etc.) (n = 37), various diseases (n = 31) and accidents (n = 30). Nineteen participants did not know what caused their pain. Treatments for pain varied, but most had used medications alone (n = 76) or in combination with other treatments (n = 61). The prevalence of pain in the general population of Icelandic adults is similar to what has been reported. Estimates of chronic pain are towards the higher end when compared to data from other European counties, yet comparable to countries such as Norway. This raises questions about possible explanations to be looked for in genetics or cultural point of view. This population based study provides valuable information about the prevalence of pain in Iceland and also supports findings previously reported about pain in the neighboring countries.

A randomized trial of a representational intervention for cancer pain: does targeting the dyad make a difference?

OBJECTIVE: To determine the efficacy in overcoming attitudinal barriers to reporting cancer pain and using analgesics of an educational intervention presented to patients accompanied by a significant other (SO) as compared with patients alone. DESIGN: Patient-SO pairs (N = 161) were randomized to the dyad condition (patient and SO received the intervention), solo condition (patient received the intervention), or care as usual. Dyad and solo conditions received the intervention at baseline (T1) and 2 and 4 weeks later. MAIN OUTCOME MEASURES: Patients' and SOs' attitudes about analgesic use and patients' pain outcomes (pain severity, pain relief, interference with life, negative mood, and global quality of life [QOL]) at T1, 5 weeks later (T2), and 9 weeks later (T3). RESULTS: Completers' analyses revealed no significant differences between groups at T2. At T3, patients in the dyad and the solo groups showed greater decreases in attitudinal barriers as compared with controls. T1-T3 changes in patients' barriers mediated between the dyad and solo interventions and pain severity, pain relief, pain interference, negative mood, and global QOL. CONCLUSION: The intervention was no more efficacious when it was presented to dyads than to patients alone. Conditions under which SOs should be included in interventions need to be determined.

A randomized trial of a tailored barriers intervention for Cancer Information Service (CIS) callers in pain.

Cancer pain management can be improved by overcoming patients' attitudinal barriers to reporting pain and using analgesics. A simple cost-effective barriers intervention designed to reach a large number of persons with cancer has not yet been tested. Such an intervention should be tested against barriers' assessment-alone, as well as no-treatment control. The purpose of this study was to test the efficacy and the cost effectiveness of a tailored barriers intervention (TBI), an educational intervention tailored to participants' attitudinal barriers toward reporting pain and using analgesics. This was a randomized three-group (TBI, assessment-alone, or control) trial with measures at baseline and 28 days later conducted at the NorthCentral and Heartland offices of the Cancer Information Service (CIS), an NCI program that provides information to persons seeking answers to cancer-related questions. Participants (1256 adult CIS callers diagnosed with cancer with moderate to severe pain in the past week) joined the study and were randomized. Of these participants, 970 (77.23%) provided follow-up data. The TBI consisted of educational messages tailored to each participant's attitudinal barriers, delivered orally over the telephone, followed by a printed mailed copy. The outcome measures were attitudinal barriers to pain management, as well as pain outcomes (duration, severity, and interference with life activities). At follow-up the TBI group had significantly lower attitudinal barriers scores compared to assessment-alone and control, but the groups did not differ on the pain outcome variables. TBI and assessment-alone had similar cost effectiveness. The TBI needs to be strengthened to achieve reductions in pain severity.

Simpson's paradox and experimental research.

BACKGROUND: Experimental research in nursing has increased considerably in recent years. To improve the quality of such research, it is critical to reduce threats to internal validity. One threat that has received inadequate attention in the nursing literature is Simpson's paradox--a case of extreme confounding that can lead to erroneous conclusions about the effects of an experimental intervention. In fact, it can lead to a conclusion about an intervention effect that is the opposite of the correct inference. APPROACH: The aims of this study were to describe Simpson's paradox, provide a hypothetical example, and discuss approaches to avoiding the paradox. RESULTS: The paradox is due to the combination of an overlooked confounding variable and a disproportionate allocation of that variable among experimental groups. Different designs and analysis approaches that can be used to avoid the paradox are presented. DISCUSSION: Simpson's paradox can be avoided by selecting an appropriate experimental design and analysis that incorporates the confounding variable in such a way as to obtain unconfounded estimates of treatment effects, thus more accurately answering the research question.

Attitudinal barriers to cancer pain management in the Icelandic population.

The purpose of this study was to evaluate attitudinal barriers to cancer pain management in a random sample of 1,284 adults drawn from a national registry. Data were collected with a postal survey, and 599 (46.6%) surveys were completed. Barriers were evaluated with the Icelandic Barriers Questionnaire-II. The mean (SD) age of respondents was 45.28 (17.14) years, and 55.8% were women. Their mean (SD) length of education was 13.81 (4.27) years. Approximately half (55.6%) had personal experience of cancer; of those, 95.7% had a relative or a close friend so diagnosed, and in addition, 33 (10%) had been diagnosed themselves. The mean (SD) Icelandic Barriers Questionnaire-II score was 2.16 (0.77) on a scale of 0 to 5, with higher scores indicating stronger attitudinal barriers. Education was inversely related to barriers, and age was inversely related to 1 specific barrier (fatalistic beliefs). Those who had personal experience of cancer had lower barriers than those who did not. There seem to be substantial attitudinal barriers to cancer pain management among the general population of Iceland, and stronger than previously described in the United States. This points to the importance of addressing barriers among lay people because these barriers may interfere with good pain management practices.

Evaluation of the Symptom Representation Questionnaire (SRQ) for assessing cancer-related symptoms.

Multidimensional, multisymptom approaches to cancer symptom assessment and management have been emphasized across health disciplines. However, each dimension that is assessed significantly increases patient/subject burden. Efficient, reliable, and valid assessment of the critical dimensions of patients' most salient symptoms is important in clinical and research settings. The Symptom Representation Questionnaire (SRQ), derived from information processing theory, assesses critical cognitive and emotional factors that are known to influence coping and outcomes. The SRQ was developed and evaluated in a three-phase process: (1) item selection, modification, and review by theoretical and clinical experts; (2) pilot evaluation of feasibility and psychometric properties; and (3) large sample psychometric evaluation. In Phase 3, members (n=713) of the National Ovarian Cancer Coalition participated via mailed surveys. Internal consistency was good for all subscales (alpha=0.63-0.88). The internal structure of the SRQ was theoretically consistent except that emotional representation, identity, and consequence items all loaded onto a single factor. Between-group comparisons supported construct validity: Representations differed between long-term survivors and women with active disease. Finally, there were significant correlations between SRQ subscales and Symptom Interference and Life Satisfaction. The SRQ appears to be a psychometrically sound instrument for assessing representations of cancer-related symptoms. This instrument could play an essential role in advancing knowledge of the relationships among representations of symptoms, symptom management processes, and symptom-related outcomes. It could also be used in intervention research when changes in symptom representations are hypothesized to mediate changes in outcomes as a result of psychoeducational interventions.

Benchmarking the effectiveness of psychotherapy treatment for adult depression in a managed care environment: a preliminary study.

This preliminary study evaluated the effectiveness of psychotherapy treatment for adult clinical depression provided in a natural setting by benchmarking the clinical outcomes in a managed care environment against effect size estimates observed in published clinical trials. Overall results suggest that effect size estimates of effectiveness in a managed care context were comparable to effect size estimates of efficacy observed in clinical trials. Relative to the 1-tailed 95th-percentile critical effect size estimates, effectiveness of treatment provided in this setting was observed to be between 80% (patients with comorbidity and without antidepressants) and 112% (patients without comorbidity concurrently on antidepressants) as compared to the benchmarks. Because the nature of the treatments delivered in the managed care environment were unknown, it was not possible to make conclusions about treatments. However, while replications are warranted, concerns that psychotherapy delivered in a naturalistic setting is inferior to treatments delivered in clinical trials appear unjustified.