***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: & NA ; The objective was to investigate the relationship between pain relief scores produced by placebo and by active interventions in r and omised controlled trials ( RCTs ) . Individual patient categorical pain relief scores from 5 placebo‐controlled single‐dose parallel‐group RCTs in acute postoperative pain were used to calculate the percentage of the maximum possible pain relief score ( % maxTOTPAR ) for the different treatments . One hundred and thirty of the 525 patients in the 5 trials had a placebo .  Individual patients ' scores with placebo varied from 0 to 100 % of the maximum possible pain relief . The proportion who obtained more than 50 % of the maximum possible pain relief with placebo varied from 7 % to 37 % across the trials ; with the active drugs the variation was from 5 to 63 % . Mean placebo scores were related to the mean score for the active treatments in each study ; the higher the mean active score , the higher the mean placebo score . This relationship disappeared when median values were used . Medical folklore has it that the amount of relief obtained with placebo is one‐third of the maximum possible ( and does not vary ) , and that one‐third of patients respond to placebo . The results show that the amount of relief obtained with placebo varies considerably between patients , that 38 % of patients obtained more than 10 % of the maximum possible relief , and 16 % obtained greater than 50 % . In double‐blind , r and omised parallel‐group studies of high quality placebo scores should not vary . Despite these conditions being met the placebo scores did vary . The previous explanation , of a relationship between the mean placebo scores and the mean scores for the active treatments was not supported In this report , we examine the potential risk factors for both the incidence and the number of placebo adverse reactions among patients who were enrolled in the placebo control group in a multicenter clinical trial ( n = 491 ) . Of the nine baseline covariates analyzed , only clinical center was significantly related to both the presence and the number of adverse reactions .  Placebo  group patients at clinical centers 5 and 7 were more than twice as likely to experience an adverse reaction than were patients at clinical center 1 . This finding , in light of the intensive effort we made to st and ardize the methods for adverse reaction detection and management , points out the difficulty in controlling for the inherent differences in the characteristics of the patient population s and clinic personnel at the clinical centers in a multicenter trial , and reinforces the need to stratify by clinical center prior to r and omization Forty-eight patients with anxiety states were treated with oxazepam ( Serenid-D ) , which was administered in tablets of three different colours — red , yellow , and green . Every patient received one week 's treatment with each colour , according to a r and om programme . A latin square design was used to ensure complete balance between the colours and between the weeks . The patients ' symptoms were categorized and then assessed by both weekly physicians ' ratings and daily self-rating , which showed close agreement . Colour preference was shown on both these scales in that symptoms of anxiety were most improved with green , whereas depressive symptoms appeared to respond best to yellow . Such colour preferences , however , did not reach levels of statistical significance , except for phobias as rated on the physicians ' assessment . The results indicate that colour may play a part in the response to a drug Patient blindability was examined in clinical , psychopharmacological , double-blind , placebo-controlled trials involving medications for obsessive-compulsive disorder and major depression . Based on the presence of clinical improvement and side effects , patients were able to determine correctly whether they took medication versus placebo . On the basis of these preliminary findings , the authors question the blindability of patients in clinical trials . Implication s for the continued use of double-blind , placebo-controlled trials are discussed To determine whether informed consent in a therapeutic trial modifies the analgesic effect of naproxen and placebo , we conducted a prospect i ve , r and omised , single dose , placebo-controlled trial . Patients were r and omly selected to receive or not information concerning the study . All patients included were then given a single dose of naproxen and placebo according to a crossover , double-blind design . Forty-nine patients with mild or moderate cancer pain which did not need narcotic analgesics entered the study . Twenty-five received both treatments without any information and constituted the uninformed group . Twenty-four had a complete information about the trial ; six refused to participate . The 18 others constituted the informed-consent group . Visual analogue scales of pain before and 30 , 60 , 120 and 180 min after the intake of naproxen and placebo were recorded . As an analgesic , naproxen was more effective than placebo in both groups of patients ( p = 0.001 ) . For naproxen as well as for placebo , the analgesic effect was better in the informed-consent group compared to the uninformed group ( p = 0.012 ) . The difference in therapeutic activity between naproxen and placebo was moderately higher in the uninformed patients ( p = 0.08 ) . We concluded that , in contrast with parallel studies , giving information in a crossover , placebo-controlled trial may increase the apparent efficacy of both the tested agent and the placebo , and decrease the perceived difference the two Few studies have attempted to describe the effect of placebo therapy on  chronic pain .  In this study pain was assessed daily , for 25 days , in 23 patients with rheumatoid arthritis . Patients received placebo during the last 9 days of the study . Pain scores during the first 16 days acted as a baseline from which each patient 's response to placebo could be determined . Patients completed Form B of the Eysenck Personality Inventory on entry into the study , a pre-treatment expectation rating scale and a post-treatment assessment scale .  Five patients were excluded from analysis because of trends in their baseline pain scores .  Of the remaining patients , nine responded positively to placebo and five responded negatively . Four patients reported no significant change in pain and were found to be more introverted than both the negative ( p less than 0.05 ) and positive placebo responders . Consequently , the degree of extraversion might prove a useful predictor of therapeutic response . No significant relationship was found between the patients expectation of therapy and the observed response which suggests that therapeutic outcome is not pre-determined . However , the patients assessment of therapeutic effect was closely related to the observed response ( p less than 0.05 ) . Neuroticism was greater in patients with side-effects than those without ( p less than 0.05 ) and might be utilized as a means of detecting those patients most likely to complain of unrelated symptoms while on a new therapy . The different placebo responses observed draws attention to the difficulties in making therapeutic judgements in clinical practice and of assessing efficacy in drug trials OBJECTIVE We studied recent nonsteroidal anti-inflammatory drug ( NSAID ) r and omized control trials of arthritis to identify the age and number of older people ( > or = 65 years ) and to document the way information on age was presented . We hypothesized that older people , who are most likely to take NSAIDs are underrepresented and underreported . STUDY SELECTION AND DATA EXTRACTION All NSAID articles ( n = 1008 ) in MEDLINE between September 1987 and May 1990 were identified . Eighty-three trials employing NSAIDs in a r and omized control trial of arthritis reported in 73 articles were identified and studied in detail for age-related information . RESULTS A total of 9664 subjects with a female-to-male ratio of 2.3:1 were enrolled . Forty-four trials studied osteoarthritis ( 53.0 % ) , 37 studied rheumatoid arthritis ( 44.6 % ) , and two studied both conditions ( 2.4 % ) . More than half of the studies review ed included people 65 years of age or older , only 207 people in this older age group could be identified ( 2.1 % ) . While there was inclusion of the ' young-old ' ( 65 to 74 years of age ) , only 14 of the 9664 people studied were between 75 and 84 years of age , and no one 85 years or older could be identified . The inclusion of the young-old is documented by the weighted mean age that ranged from 59.6 to 64.9 years for patients with osteoarthritis ( mean , 62.9 ; SD , 1.67 ) and from 47.4 to 53.0 years ( mean , 49.9 ; SD , 2.16 ) for those with rheumatoid arthritis . CONCLUSION We demonstrate that older people , who represent a high proportion of the population treated with NSAIDs in practice , are generally omitted from drug trials . Recommendations design ed to improve the reporting of age information to make clinical trials more informative and applicable to older people are presented BACKGROUND To study the relation between reported drug performance in published trials and support of the trials by the manufacturer of the drug under evaluation , we studied a sample of trials of  nonsteroidal anti-inflammatory drugs ( NSAIDs ) used in the treatment of arthritis . METHODS All r and omized control trials of NSAIDs published between September 1987 and May 1990 identified by MEDLINE were review ed . If an article met the following criteria ( n = 61 ) , it was selected : trials involving adult patients with osteoarthritis or rheumatoid arthritis ( n = 180 ) , use of nonsalicylate NSAIDs marketed in the United States ( n = 101 ) , r and omized control trial ( n = 81 ) , duration of the trial 4 or more days ( n = 78 ) , and use of an efficacy outcome measure ( n = 61 ) . Review ers , " blinded " to manufacturer status , evaluated the narrative interpretation of results and extracted numeric data on efficacy and toxicity . Manufacturer-associated trials were defined as those that acknowledged an association with a pharmaceutical manufacturer . Because of the scarcity of non-manufacturer-associated trials ( n = 9 ) , we report only on the manufacturer-associated articles . RESULTS Fifty-two publications ( 85.2 % ) representing 56 trials were associated with a manufacturer . The manufacturer-associated drug was reported as comparable with ( 71.4 % ) or superior to ( 28.6 % ) the comparison drug in all 56 trials . These narrative cl aims of superiority were usually justified with trial data . Of the trials identifying one drug as less toxic ( n = 22 ) , the manufacturer-associated drug 's safety was reported as superior to the comparison drug in 86.4 % of cases . Justification for the narrative interpretation of the trial findings regarding less toxicity was provided in only 12 ( 54.5 % ) of 22 trials . CONCLUSION The manufacturer-associated NSAID is almost always reported as being equal or superior in efficacy and toxicity to the comparison drug . These cl aims of superiority , especially in regard to side effect profiles , are often not supported by trial data . These data raise concerns about selective publication or biased interpretation of results in manufacturer-associated trials 
    Output:
    
Although reports of central nervous system adverse effects were more frequent in the comparative trials , this difference was not significant .
Including a placebo group in a RCT changes how patients rate the efficacy and adverse effects of their therapy .