***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: Our purpose was to evaluate the analgesic efficacy of single oral doses of ketoprofen 25 , 50 , and 100 mg compared with aspirin 650 mg and placebo in the relief of moderate to severe postepisiotomy , uterine cramping , or cesarean section pain . One hundred and fifty-six patients participated in a r and omized , double-blind , stratified , parallel-group study . They were observed over a six-hour period by one nurse-observer . Several of the st and ard summary measures of analgesia were derived from the interview data , including the sum of pain intensity differences ( SPID ) and the sum of the hourly relief values ( TOTAL ) . The study showed significant differences between aspirin and placebo for four-hour SPID and several other parameters and between ketoprofen at all dose levels and placebo for the four- and six-hour SPID and many other parameters . The two higher doses of ketoprofen were significantly more effective than aspirin as as assessed by the four- and six-hour SPID , TOTAL , and other summary measures . The low dose of ketoprofen , although not significantly different from aspirin for SPID and TOTAL , showed a significantly faster onset of relief and had a better global rating . This study suggests that 50 mg of ketoprofen may be the clinical dose of choice as an analgesic . There were no adverse effects reported The analgesic activity of 300 and 600 mg . of flufenisal , a fluorinated phenyl derivative of aspirin , was compared to 600 and 1,200 mg . of aspirin and to placebo under r and omized double‐blind conditions in 100 patients with pain due to episiotomy . Over the 8 hours of evaluation , pain reduction greater than 50 per cent was observed in at least 60 per cent of patients treated with both doses of flufenisal , whereas it was 40 per cent with 600 mg . of aspirin , 55 per cent with 1,200 mg . of aspirin , and 26 per cent with placebo . On a time‐effect basis with the two grade d doses of both flufenisal and aspirin  , pain relief , as measured by pain intensity differences , was similar with respect to time of onset and maximal effect attained . However , with the flufenisal  significant analgesia persisted at the eighth hour ( p < 0.02 ) , while with the aspirin there was none after the fifth hour . On the basis of these data , flufenisal at one fourth to one half the dose of aspirin appears to provide analgesia of almost double the duration of aspirin and is equivalent to aspirin  in time of onset and degree of relief of episiotomy pain . This raises the possibility that in some clinical conditions flufenisal may be effective in providing prolonged pain relief BACKGROUND High-dose aspirin ( ≥500 mg daily ) reduces long-term incidence of colorectal cancer  , but adverse effects might limit its potential for long-term prevention . The long-term effectiveness of lower doses ( 75 - 300 mg daily ) is unknown . We assessed the effects of aspirin on incidence and mortality due to  colorectal cancer in relation to dose , duration of treatment , and site of tumour . METHODS We followed up four r and omised trials of aspirin versus control in primary ( Thrombosis Prevention Trial , British Doctors Aspirin Trial ) and secondary ( Swedish Aspirin Low Dose Trial , UK-TIA Aspirin Trial ) prevention of vascular events and one trial of different doses of aspirin  ( Dutch TIA Aspirin Trial ) and established the effect of aspirin on risk of colorectal cancer over 20 years during and after the trials by analysis of pooled individual patient data . RESULTS In the four trials of aspirin versus control ( mean duration of scheduled treatment 6·0 years ) , 391 ( 2·8 % ) of 14 033 patients had colorectal cancer during a median follow-up of 18·3 years . Allocation to aspirin  reduced the 20-year risk of colon cancer ( incidence hazard ratio [ HR ] 0·76 , 0·60 - 0·96 , p=0·02 ; mortality HR 0·65 , 0·48 - 0·88 , p=0·005 ) , but not rectal cancer ( 0·90 , 0·63 - 1·30 , p=0·58 ; 0·80 , 0·50 - 1·28 , p=0·35 ) . Where subsite data were available , aspirin reduced risk of cancer of the proximal colon ( 0·45 , 0·28 - 0·74 , p=0·001 ; 0·34 , 0·18 - 0·66 , p=0·001 ) , but not the distal colon ( 1·10 , 0·73 - 1·64 , p=0·66 ; 1·21 , 0·66 - 2·24 , p=0·54 ; for incidence difference p=0·04 , for mortality difference p=0·01 ) . However , benefit increased with scheduled duration of treatment , such that allocation to aspirin of 5 years or longer reduced risk of proximal colon cancer by about 70 % ( 0·35 , 0·20 - 0·63 ; 0·24 , 0·11 - 0·52 ; both p<0·0001 ) and also reduced risk of rectal cancer ( 0·58 , 0·36 - 0·92 , p=0·02 ; 0·47 , 0·26 - 0·87 , p=0·01 ) . There was no increase in benefit at doses of aspirin greater than 75 mg daily , with an absolute reduction of 1·76 % ( 0·61 - 2·91 ; p=0·001 ) in 20-year risk of any fatal colorectal cancer after 5-years scheduled treatment with 75 - 300 mg daily . However , risk of fatal colorectal cancer was higher on 30 mg versus 283 mg daily on long-term follow-up of the Dutch TIA trial ( odds ratio 2·02 , 0·70 - 6·05 , p=0·15 ) . INTERPRETATION Aspirin taken for several years at doses of at least 75 mg daily reduced long-term incidence and mortality due to colorectal cancer . Benefit was greatest for cancers of the proximal colon , which are not otherwise prevented effectively by screening with sigmoidoscopy or colonoscopy . FUNDING None Abstract A previously established relationship for deriving dichotomous from continuous information in r and omised controlled trials ( RCTs ) of analgesics has been tested using an independent data set . Individual patient information from 18 RCTs of parallel‐group design in acute postoperative pain ( after abdominal , gynaecological and oral surgery ) was used to calculate the percentage of the maximum possible pain relief score  ( % maxTOTPAR ) and the proportion of patients with > 50%maxTOTPAR for the different treatments . The relationship between the measures was investigated in 85 treatments with over 3400 patients . In 80 of 85 treatments ( 94 % ) agreement between calculated and actual number of patients with > 50%maxTOTPAR was within four patients per treatment and in 72 ( 85 % ) was within three ( average of 40 patients per treatment , range 21–58 patients ) . Summing the positive and negative differences between actual and calculated numbers of patients with > 50%maxTOTPAR gave an average difference of 0.30 patients per treatment arm . Reports of RCTs of analgesics frequently describe results of studies in the form of mean derived indices , rather than using discontinuous events , such as number or proportion of patients with 50 % pain relief . Because mean data inadequately describe information with a non‐normal distribution , combining mean data in systematic review s may compromise the results . Showing that dichotomous data can reliably be derived from mean data in acute pain studies enables data published as means to be used for quantitative systematic review s which require data in dichotomous form The purpose of this study was to evaluate the analgesic efficacy and adverse effect liability of single oral doses of indoprofen , 50 mg , 100 mg , and 200 mg , compared with aspirin , 300 mg and 600 mg , and placebo in the relief of moderate to severe postpartum pain . Two hundred-ten patients entered a r and omized , double-blind , parallel group study and were evaluated over a six-hour period by a single nurse-observer . There was a significant imbalance in the distribution of pain types across treatments that compromises the interpretation of the results . In addition to analyzing the data from all patients , the subsets with episiotomy/cesarean section pain and uterine cramp pain were examined separately . The latter group had too few patients to permit distinction between drugs . The 100 mg and 200 mg doses of indoprofen were significantly ( P less than or equal to .05 ) more effective than placebo for many variables including the following summary values : sum of pain intensity difference ( SPID ) , sum of hourly relief values ( TOTPAR ) , and % SPID for all patients as well as in the subset of patients with episiotomy/cesarean section pain . Aspirin , 600 mg , was also significantly more effective than placebo for many of the same measures of analgesia in the episiotomy/cesarean section subset . Pairwise differences were also seen between placebo and aspirin , 300 mg , but on fewer variables . Indoprofen , 100 mg , was significantly more effective than aspirin , 600 mg , at hour 6 for pain intensity difference ( PID ) in the episiotomy/cesarean section subset . The effect of indoprofen appeared to plateau above 100 mg . ( ABSTRACT TRUNCATED AT 250 WORDS & NA ; Reports of RCTs of analgesics frequently describe results of studies in the form of mean derived indices , rather than using discontinuous events — such as number or proportion of patients with 50 % pain relief . Because mean data inadequately describe information with a non‐normal distribution , combining mean data in systematic review s may compromise the results . Showing that dichotomous data can reliably be derived from mean data , at least in acute pain models , indicates that more meaningful overviews or meta‐ analysis may be possible . This study investigated the relationship between continuous and dichotomous analgesic measures in a set of individual patient data , and then used that relationship to derive dichotomous from continuous information in r and omised controlled trials ( RCTs ) of analgesics .  Individual patient information from 13 RCTs of parallel‐group and crossover design in acute postoperative pain was used to calculate the percentage of the maximum possible pain relief score ( % maxTOTPAR ) and the proportion of patients with greater than 50 % pain relief ( > 50%maxTOTPAR ) for the different treatments . The relationship between the measures was investigated in 45 actual treatments and 10 000 treatments simulated using the underlying actual distribution ; 1283 patients had 45 separate treatments . Mean % maxTOTPAR correlated with the proportion of patients with > 50%maxTOTPAR ( r2 = 0.90 ) . The relationship calculated from all the 45 treatments predicted to within three patients the number of patients with more than 50 % pain relief in 42 of 45 treatments , and 98.8 % of 10 000 simulated treatments . For seven effective treatments , actual numbers‐needed‐to‐treat ( NNT ) to achieve > 50%maxTOTPAR compared with placebo were very similar to those derived from calculated data A double-blind , placebo-controlled , parallel group study was performed to compare the analgesic efficacy of diclofenac potassium ( 25 , 50 , or 100 mg ) with that of aspirin ( 650 mg ) , or placebo .  Two hundred fifty-five in patients with severe postepisiotomy pain were r and omly assigned to receive a single oral dose of one of the four active treatments or placebo .  Analgesia was assessed over an 8-hour period . Treatments were compared on the basis of st and ard scales for pain intensity and relief and a number of derived variables based on these data , as well as two global ratings of the study medication . All active treatments were effective analgesics statistically superior to placebo for many hourly and summary measures , including the global ratings . Diclofenac potassium ( 50 and 100 mg ) was statistically significantly superior to aspirin at half-hour and for many other hourly scores from hour 3 on . The 4− and 8-hour sum of the pain intensity difference and total pain relief scores reflected the superiority of diclofenac potassium to aspirin . In addition , the 100-mg dose was significantly more efficacious than the 25-mg dose of diclofenac potassium . The probability of obtaining onset was significantly better for all active treatments than for placebo ; however , the median onset times were similar for all treatments . The duration of effect , as measured by mean pain intensity difference and relief scores , was better for diclofenac potassium than aspirin , and these differences were significant for the 50− and 100-mg doses . The probability of pain returning to baseline was significantly less for the diclofenac groups than for placebo or aspirin groups . In addition , significantly fewer patients treated with diclofenac ( 25 , 50 , or 100 mg ) or aspirin ( 650 mg ) required remedication during the 8-hour study period as compared with those treated with placebo . Diclofenac potassium is an effective analgesic in the range of aspirin ( 650 mg ) at the 25-mg dose and superior in efficacy and longer lasting than 
    Output:
    
We found low- quality evidence to suggest that single dose aspirin compared with placebo can increase pain relief in women with perineal pain post-episiotomy .
Very low- quality evidence also suggested that aspirin can reduce the need for additional analgesia , without increasing maternal adverse effects .
RCTs excluded breastfeeding women so there is no evidence to assess the effects of aspirin on neonatal adverse effects or breastfeeding .
With international guidance recommending mothers initiate breastfeeding within one hour of birth , and exclusively breastfeed for the first six months , the evidence from this review is not applicable to current recommended best practice .
Aspirin may be considered for use in non-breastfeeding women with post-episiotomy perineal pain .
It is considered most likely that if RCTs are conducted in the future they could compare aspirin with other pain relievers .