The Initial Evaluation Of The Impact Of Pain: Meta Analysis And Experimental Research

A growing body of research indicates that people’s beliefs about pain influence how they respond to both noxious experimental stimuli and ongoing chronic pain. The transactional model (R. S. Lazarus,1998; R.S. Lazarus,1999) has been a useful approach for conceptualizing the impact of beliefs or appraisals on responses to stressors including pain. From this perspective, upon confronting potential stressors, people make initial evaluations about events to assess their implications for well-being. While not exhaustive, primary appraisals or beliefs include pre-existing notions that stressors are sources of (1) threat for potential future damage or (2) challenge or opportunity for future growth, mastery, or profit. Although numerous studies have linked threat appraisals, in particular, to less adaptive functioning in experimental and chronic pain samples, researchers have reported variable effects of appraisal on functioning.Given inconsistencies in such research, the main purpose of this thesis was to perform meta-analyses to evaluate overall strengths of relation between threat and challenge appraisal and i) responses to experimental pain as well as ii) key outcomes of chronic pain (i.e., pain severity, functional impairment, affective distress). In addition, the research was designed to identify potential moderating effects of specific sample characteristics and methodological factors on associations between appraisal and pain responses within both experimental pain and chronic pain literatures. Secondly, the thesis also manipulated challenge appraisal of individuals and explore how challenge appraisal influence pain response.Systematic searches resulted in the initial consideration of2383studies. Screening of these studies for appropriate papers resulted in the retention of22studies for the laboratory pain meta-analysis (N=2,031) and59studies for the chronic pain meta-analysis (N=9,135). Rates of inter-rater agreement were satisfactory for study inclusion/exclusion from a meta-analysis (k=.91) and the coding of variables used in the meta-analyses (k=.88).Data analyses of experimental pain studies indicated elevations in threat appraisal were related to significant overall increases in reported pain, reduced pain tolerance and high levels of passive coping. Method of measuring appraisal (experimental manipulation versus self-report) as well as type of noxious stimulus (cold versus heat versus other) and duration of noxious stimulation (less versus more than30seconds) moderated some of these associations. Challenge appraisals were related to more pain tolerance and less passive coping but not pain intensity.For chronic pain studies, threat appraisals had significant positive overall correlations with pain intensity, impairment, affective distress and passive coping as well as negative relations to active coping. The pattern of associations between challenge appraisals and outcomes was largely complementary. Appraisal scale used and gender were consistent moderators of appraisal-outcome relations in chronic pain samples. Finally, results of trim and fill analyses conducted to adjust for effects of publication bias within each meta-analysis indicated that adjusted effect sizes for each appraisal-outcome associations were very similar to unadjusted effect sizes. Taken together, findings from the two meta-analyses indicated appraisals of pain as a source of potential damage or opportunity have robust associations with responses to acute laboratory pain and ongoing chronic pain.A secondary purpose of this research was to address the lack of experimental research designed to assess the causal impact of challenge appraisals on pain perception and coping, In Study2, a sample of105undergraduates (37men,68women) were randomly assessed to experimental manipulations in which they read about how persistence at difficult tasks is related to future life success (challenge appraisal condition), causes and consequences of frostbite due to exposure to cold (higher threat condition) or the safety of the cold pressor test (lower threat condition) before immersing their hand in very low temperature water for as long as possible. It was hypothesized that participants assigned to the challenge appraisal condition would have better pain tolerance and report using more cognitive coping than participants in either of the threat conditions while those in the higher threat condition would show the lowest pain tolerance and report the least cognitive coping.The result demonstrated that between group different for pain intensity was significant with F (2,102)=3.906, p=0.023. Higher threat group reported higher the strongest pain intensity, intensity when draw back the hand and average pain intensity than lower threat group. Group difference for pain tolerance was also significant with F (2,102)=3.175, p=0.046. Challenge group had longer tolerance time than higher threat group but no significant difference between challenge group and lower threat group, as well as higher threat group and lower threat group. Challenge group tended to use more reinterpretation coping strategies than higher and lower threat groups with F (2,102)=3.906, p=0.023. Challenge group tended to use more diverting coping strategies than lower threat group with F (2.102)=3.930, p=0.023, and more coping self statement coping strategies than higher threat group with F (2,102)=5.431, p=0.006. Threat group tended to less use ignore as a coping strategies compared with the other two groups with F (2,102)=6.263, p=0.003. No significant differences among three groups on catastrophizing and acceptance. Correlation analyses revealed that challenge appraisal was positively correlated with pain intensity, pain tolerance time and active coping strategies but not correlated with pain intensity. Threat appraisal was positively correlated with pain intensity and catastropzhing but negatively correlated with pain tolerance.No significant pain intensity difference was found between challenge group and the other two groups. Challenge group had longer pain tolerance time than higher threat group. In addition, challenge group tended to use reinterpretation, diverting, coping self statement and ignore as coping strategies. Threat appraisal caused higher pain intensity reporting and was associated with shorter pain tolerance time and higher catastrophizing.The present research creatively used meta-analyses to summarize the association among primary appraisal and pain respond, and provided robust effect sizes. Secondly, the research was the first to manipulate the challenge appraisal based on Transactional model. Theoretically, the research provided strong evidence for the Transactional model.