***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background Decreased pain represents a clinical ly important outcome following  arthroscopic knee surgery .  However , little is known about preoperative mood and attitudinal factors and their potential relationship with pain outcomes . Purpose This prospect i ve , longitudinal study investigated the influence of preoperative depression , stress , and optimism on pain severity and interference with functioning , controlling for relevant demographic and clinical factors 1 year postoperatively . Methods Participants ( N = 180 , mean age = 48.2 years ) completed scales assessing pain severity and interference  both preoperatively and postoperatively .  Demographics , depression , stress , optimism , and body mass index were assessed preoperatively . Physicians assessed extent of knee osteoarthritis during surgery . Results Hierarchical regression analyses controlling for relevant demographic and clinical variables revealed that optimism and stress were significant predictors of pain severity at 1 year but not pain interference . Extent of osteoarthritis predicted pain interference . Conclusions These findings support that optimism and stress are important predictors of patient-rated pain severity . They do not , however , predict the extent to which pain interferes with daily functioning Abstract Background Chronic pain is associated with emotional problems as well as difficulties in cognitive functioning . Prior experimental studies have shown that optimism , the tendency to expect that good things happen in the future , and positive emotions can counteract pain‐induced task performance deficits in healthy participants . More specifically , induced optimism was found to buffer against the negative effects of experimental pain on executive functioning . This clinical experiment examined whether this beneficial effect can be extended to a chronic pain population . Methods Patients ( N = 122 ) were r and omized to a  positive psychology Internet‐based intervention ( PPI ; n = 74 ) or a waiting list control condition ( WLC ; n = 48 ) . The PPI consisted of positive psychology exercises that particularly target optimism , positive emotions and self‐compassion . Results Results demonstrated that patients in the PPI condition scored higher on happiness , optimism , positive future expectancies , positive affect , self‐compassion and ability to live a desired life despite pain , and scored lower on pain catastrophizing , depression and anxiety compared to patients in the WLC condition . However , executive task performance did not improve following completion of the PPI , compared to the WLC condition . Conclusions Despite the lack of evidence that positive emotions and optimism can improve executive task performance in chronic pain patients , this study did convincingly demonstrate that it is possible to increase positive emotions and optimism in chronic pain patients with an online positive psychology intervention . It is imperative to further explore amendable psychological factors that may reduce the negative impact of pain on executive functioning . Significance We demonstrated that an Internet‐based positive psychology intervention strengthens optimism and positive emotions in chronic pain patients . These emotional improvements are not associated with improved executive task performance . As pain itself often can not be relieved , it is imperative to have techniques to reduce the burden of living with chronic pain Objectives : To assess the contribution of important psychological re sources ( i.e. optimism , pessimism , control beliefs ) to the psychological well-being of older adults with Osteoarthritis ( OA ) ; to assess the direct and mediated association of these psychosocial re sources to outcomes ( depressive symptoms , life satisfaction , and self-esteem ) . These objectives are important because OA is a significant stressor , treatments are limited , and psychological functioning is at risk for those coping with the condition , even compared to other chronic illnesses . Method : A cross-sectional survey of 160 community-dwelling older adults with OA ( 81 % women ) . Participants were not r and omly selected , but nonetheless reflected the demographic makeup of the selection area . Results : Ordinary least squares regression analyses using the PROCESS macro revealed that optimism and pessimism were associated with higher depressive symptoms and lower self-esteem indirectly through constraints beliefs . The analysis of life satisfaction showed that optimism and pessimism were each partially mediated through mastery and constraints beliefs . Discussion : These results suggest that prior research , which has assessed these psychological re sources as having singular relationships to outcomes , may have underestimated the importance of the relationship between these variables . We discuss possible points of intervention for older adults with OA who may experience increasing constraints beliefs over time Background : Few epidemiological studies have prospect ively investigated preoperative and surgical risk factors for acute postoperative pain after surgery for breast cancer . We investigated demographic , psychological , pain-related and surgical risk factors in women undergoing resectional surgery for breast cancer . Methods : Primary outcomes were pain severity , at rest ( PAR ) and movement-evoked pain ( MEP ) , in the first postoperative week . Results : In 338 women undergoing surgery , those with chronic preoperative pain were three times more likely to report moderate to severe MEP after breast cancer surgery ( OR 3.18 , 95 % CI 1.45–6.99 ) . Increased psychological ‘ robustness ’ , a composite variable representing positive affect and dispositional optimism , was associated with lower intensity acute postoperative PAR ( OR 0.63 , 95 % CI 0.48–0.82 ) and MEP ( OR 0.71 , 95 % CI 0.54–0.93 ) . Sentinel lymph node biopsy ( SLNB ) and intraoperative nerve division were associated with reduced postoperative pain . No relationship was found between preoperative neuropathic pain and acute pain outcomes ; altered sensations and numbness postoperatively were more common after axillary sample or clearance compared with SLNB . Conclusion : Chronic preoperative pain , axillary surgery and psychological robustness significantly predicted acute pain outcomes after surgery for breast cancer . Preoperative identification and targeted intervention of subgroups at risk could enhance the recovery trajectory in cancer survivors • STUDY DESIGN : Secondary analysis of prospect ively collected data . • BACKGROUND : An abundance of evidence has highlighted the influence of pain catastrophizing and fear avoidance on clinical outcomes . Less is known about the interaction of positive psychological re sources with these pain‐associated distress factors . • OBJECTIVE : To assess whether optimism moderates the influence of pain catastrophizing and fear avoidance on 3‐month clinical outcomes in patients with shoulder pain . • METHODS : Data from 63 individuals with shoulder pain ( mean ± SD age , 38.8 ± 14.9 years ; 30 female ) were examined . Demographic , psychological , and clinical characteristics were obtained at baseline . Vali date d measures were used to assess optimism ( Life Orientation Test‐Revised ) , pain catastrophizing ( Pain Catastrophizing Scale ) , fear avoidance ( Fear‐Avoidance Beliefs Question naire physical activity subscale ) , shoulder pain intensity ( Brief Pain Inventory ) , and shoulder function ( Pennsylvania Shoulder Score function subscale ) . Shoulder pain and function were reassessed at 3 months . Regression models assessed the influence of ( 1 ) pain catastrophizing and optimism and ( 2 ) fear avoidance and optimism . The final multivariable models controlled for factors of age , sex , education , and baseline scores , and included 3‐month pain intensity and function as separate dependent variables . • RESULTS : Shoulder pain ( mean difference , ‐1.6 ; 95 % confidence interval [ CI ] : ‐2.1 , ‐1.2 ) and function ( mean difference , 2.4 ; 95 % CI : 0.3 , 4.4 ) improved over 3 months . In multivariable analyses , there was an interaction between pain catastrophizing and optimism ( & bgr ; = 0.19 ; 95 % CI : 0.02 , 0.35 ) for predicting 3‐month shoulder function ( F = 16.8 , R2 = 0.69 , P<.001 ) , but not pain ( P = .213 ) . Further examination of the interaction with the Johnson‐Neyman technique showed that higher levels of optimism lessened the influence of pain catastrophizing on function . There was no evidence of significant moderation of fear‐avoidance beliefs for 3‐month shoulder pain ( P = .090 ) or function ( P = .092 ) . • CONCLUSION : Optimism decreased the negative influence of pain catastrophizing on shoulder function , but not pain intensity . Optimism did not alter the influence of fear‐avoidance beliefs on these outcomes . • LEVEL OF EVIDENCE : Prognosis , level 2b BACKGROUND Major depression is known to be related to higher  cardiovascular mortality . However , epidemiological data regarding dispositional optimism in relation to mortality are scanty . OBJECTIVE To test whether subjects who are optimistic live longer than those who are pessimistic . DESIGN Our analysis formed part of a prospect i ve population -based cohort study in the Netherl and s ( Arnhem Elderly Study ) . SETTING General community . PARTICIPANTS Elderly subjects aged 65 to 85 years ( 999 men and women ) completed the 30-item vali date d Dutch Scale of Subjective Well-being for Older Persons , with 5 subscales : health , self-respect , morale , optimism , and contacts . A total of 941 subjects ( 466 men and 475 women ) had complete dispositional optimism data  , and these subjects were divided into quartiles . MAIN OUTCOME MEASURE Number of deaths during the follow-up period . RESULTS During the follow-up period of 9.1 years ( 1991 - 2001 ) , there were 397 deaths . Compared with subjects with a high level of pessimism , those reporting a high level of optimism had an age- and sex-adjusted hazard ratio of 0.55 ( 95 % confidence interval , 0.42 - 0.74 ; upper vs lower quartile ) for all-cause mortality . For cardiovascular mortality , the hazard ratio was 0.23 ( 95 % confidence interval , 0.10 - 0.55 ) when adjusted for age , sex , chronic disease , education , smoking , alcohol consumption , history of cardiovascular disease or hypertension , body mass index , and total cholesterol level . Protective trend relationships were observed between the level of optimism and all-cause and cardiovascular mortality ( P<.001 and P = .001 for trend , respectively ) . Interaction with sex ( P = .04 ) supported a stronger protective effect of optimism in men than women for all-cause mortality but not for cardiovascular mortality . CONCLUSIONS Our results provide support for a grade d and independent protective relationship between dispositional optimism and all-cause mortality in old age . Prevention of cardiovascular mortality accounted for much of the effect A proportion of patients do not recover fully from surgery or they develop chronic postsurgical pain . The aim of this study was to examine the incidence and predictors of unfavourable long‐term outcome after surgery using a prospect i ve cohort design Objectives : In 2009 , Gramke and colleagues have described predictive factors to preoperatively detect those at risk for moderate to severe acute postsurgical pain ( APSP ) after day surgery . The aim of the present study is to externally vali date this initial model and to improve and internally vali date a modified version of this model . Material s and Methods : Elective patients scheduled for day surgery were prospect ively enrolled from November 2008 to April 2010 . Model discrimination was quantified using the area under the receiver operating characteristic curve ( AUC ) . Model calibration was assessed by visual inspection of the calibration plot . Subsequently , we modified ( different assignment of type of surgery , different cutoff for moderate to severe APSP , continuous of dichotomized variables and testing of additional variables ) and internally vali date d this model by st and ard bootstrapping techniques . Results : A total of 1118 patients were included . The AUC for the original model was 0.81 in the derivation data set and 0.72 in our validation data set . The model showed poorly calibrated risk predictions . The AUC of the modified model was 0.82 ( optimism-corrected AUC=0.78 ) . This modified model showed good calibration . Conclusions : The original prediction model of Gramke and colleagues performed insufficiently on our cohort of out patients with respect to discrimination and calibration . Internal validation of a modified model shows promising results . In this model , preoperative pain , patient derived expected pain , and different types of surgery are the strongest predictors of moderate to severe APSP after day surgery Objective : To identify somatic and psychologic predictors of pain , functional limitations , global perceived recovery , and quality of life 6 months after surgical intervention . Summary Background Data : Recent studies have indicated that chronic pain after surgical intervention is more common than previously assumed . Several demographic and somatic predictors of long-term unfavorable outcome have been identified , but little is known about the contribution of psychologic risk factors . Methods : A prospect i ve cohort study , including 625 patients undergoing elective surgery at the University Hospital Maastricht , The Netherl and s , was conducted between February and August 2003 .  Psychologic question naires were completed preoperatively and acute postoperative pain was recorded until 4 days after the operation . Six months later , all patients received follow-up question naires to assess pain , functional limitations , global perceived recovery , and quality of life . Multivariable logistic regression analyses were used to estimate relative risk of poor outcome in terms of pain , functional limitations , and global recovery . Multivariable linear regression analysis was used to assess associations with quality of life at 6 months . Results : The most important somatic predictors of unfavorable outcome were duration of the operation and high levels of acute postoperative pain . Patients reporting high levels of pain 4 days after the operation and patients undergoing an operation of longer than 3 hours were at risk for increased pain , increased functional limitations , poor global recovery , and reported lower levels of quality of life 6 months after the operation . Psychologic variables that influenced long-term outcome were preoperative fear of surgery and optimism . Fear of the long-term consequences of the operation was associated with more pain 
    Output:
    
The review suggests that optimism is associated with less acute and chronic pain , especially since a higher percentage of beneficial associations was found with high study /publication quality and with the primary focus on this relationship .