***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: 1 . The objective of this study was to investigate the efficacy of home-medicated non-steroidal anti-inflammatory ( NSAID ) analgesics , using an electronic patient diary . Single doses of ketoprofen 25 mg and ketoprofen 50 mg were compared with ibuprofen 200 mg and placebo in the treatment of a single occasion of episodic tension-type headache , using a double-blind , r and omized , parallel group design . 2 . A total of 166 patients with headache compatible with episodic tension-type headache and no refractory headaches or contraindications to NSAIDs  were contacted by advertisements and selected by question naires . Patients performed the study at home , using an electronic diary for headache assessment , with a form to allow comments and corrections . Visual analogue scales ( VAS 10 cm ) of headache severity , five-item headache relief rating ( HRR ) scales , and time of intake of ' escape ' analgesics were scored regularly , for 4 h following intake of trial medication . 3 . VAS-scores ( n = 1407 ) and HRRs ( n = 452 ) were returned by 159 patients . Of these scores , 1.5 % were inadvertently omitted from the electronic diary or modified on the comment forms . 4 . Headache ( VAS and HRR ) improved more with all three NSAIDs than with placebo , although the effect of ibuprofen was significant for HRR only . After 2 and 4 h respectively , the reduction in VAS-ratios was 17 and 19 % with placebo , 18 and 53 % with ibuprofen 200 mg , 41 and 61 % with ketoprofen 25 mg , and 47 and 59 % with ketoprofen 50 mg . After 4 h , headache improved strongly ( highest HRR ) in 18 % of patients on placebo , 39 % on ibuprofen 200 mg , 62 % on ketoprofen 25 mg , and 55 % on ketoprofen 50 mg . Headache disappeared completely ( VAS-score = 0 ) in one patient ( 3 % ) with placebo ( after 180 min ) , 10 % with ibuprofen 200 mg ( average 211 min ) , 18 % with ketoprofen 25 mg ( 159 min ) , and 28 % with ketoprofen 50 mg ( 146 min ) . 5 . The effects of ketoprofen 50 mg were more pronounced than those of ibuprofen 200 mg , which seemed to start later . Ketoprofen 25 mg and 50 mg were very similar , suggesting a maximal effect of the lower dose . Mild to moderate adverse events were reported by 9 % of the patients , half of which occurred with ketoprofen 50 mg . Treatment of headache with ketoprofen can start with 25 mg , and possibly less . 6 . Although a direct comparative study would be necessary to determine the relative benefits of the novel electronic patient diaries over traditional paper- and -pencil methods , this study has shown the usefulness of this newer technique to detect differences in efficacy between low doses of analgesics under ambulant conditions , with very limited loss of data . Electronic patient diaries appear to be an important new attribute for the efficacy assessment of self-medicated drugs Abstract  Variability  in patients ' response to interventions in pain and other clinical setting s is large . Many explanations such as trial methods , environment or culture have been proposed , but this paper sets out to show that the main cause of the variability may be r and om chance , and that if trials are small their estimate of magnitude of effect may be incorrect , simply because of the r and om play of chance . This is highly relevant to the questions of ‘ How large do trials have to be for statistical accuracy ? ’ and ‘ How large do trials have to be for their results to be clinical ly valid ? ’ The true underlying control event rate ( CER ) and experimental event rate ( EER ) were determined from single‐dose acute pain analgesic trials in over 5000 patients . Trial group size required to obtain statistically significant and clinical ly relevant ( 0.95 probability of number‐needed‐to‐treat within ±0.5 of its true value ) results were computed using these values . Ten thous and trials using these CER and EER values were simulated using varying group sizes to investigate the variation due to r and om chance alone . Most common analgesics have EERs in the range 0.4–0.6 and CER of about 0.19 . With such efficacy , to have a 90 % chance of obtaining a statistically significant result in the correct direction requires group sizes in the range 30–60 . For clinical relevance nearly 500 patients are required in each group . Only with an extremely effective drug ( EER>0.8 ) will we be reasonably sure of obtaining a clinical ly relevant NNT with commonly used group sizes of around 40 patients per treatment arm . The simulated trials showed substantial variation in CER and EER , with the probability of obtaining the correct values improving as group size increased . We contend that much of the variability in control and experimental event rates is due to r and om chance alone . Single small trials are unlikely to be correct . If we want to be sure of getting correct ( clinical ly relevant ) results in clinical trials we must study more patients . Credible estimates of clinical efficacy are only likely to come from large trials or from pooling multiple trials of conventional ( small ) size BACKGROUND Aspirin is a widely used NSAID that has been extensively studied in numerous conditions . Nonprescription analgesics , such as aspirin , are frequently used for a wide variety of common ailments , including conditions such as dental pain and tension-type headache . OBJECTIVE We sought to compare the efficacy and safety profiles of aspirin , acetaminophen with codeine , and placebo in the treatment of post-operative dental pain and tension-type headache . METHODS These were 2 r and omized , double-blind , placebo-controlled , single-dose clinical trials that assigned participants ( 2:2:1 ) to receive either aspirin ( 1000 mg ) , acetaminophen ( 300 mg ) with codeine ( 30 mg ) , or placebo . The primary efficacy end point was the sum of pain intensity differences from baseline ( SPID ) over 6 hours for the dental pain study and over 4 hours for the tension-type headache study . Other common analgesic measures , in addition to safety , were also evaluated . RESULTS The results of the dental pain study for aspirin and acetaminophen with codeine suggest statistically significant efficacy for all measures compared with placebo at all time points . Aspirin provided statistically significant efficacy compared with acetaminophen with codeine for SPID(0 - 4 ) ( P = 0.028 ) . In the tension-type headache study , aspirin and acetaminophen with codeine provided statistically significant efficacy compared with placebo  for SPID(0 - 4 ) and SPID(0 - 6 ) ( P < 0.001 ) and for total pain relief ( P < 0.001 ) . There were no significant differences between aspirin and acetaminophen with codeine at any evaluation of SPID ( P ≥ 0.070 ) , complete relief ( P ≥ 0.179 ) , or time to meaningful relief ( P ≥ 0.245 ) . Regarding safety , there were no statistically significant differences between treatment groups in the incidence of adverse events in the dental pain and tension-type headache studies . CONCLUSIONS These 2 r and omized , double-blind , placebo-controlled studies demonstrate that treatment with aspirin ( 1000 mg ) provides statistically significant analgesic efficacy compared with placebo use and comparable efficacy with acetaminophen ( 300 mg ) with codeine ( 30 mg ) therapy after impacted third molar extraction and in tension- type headache Background . Primary headaches are underdiagnosed and undertreated , with a significant impact on social activities and work . Aim . To determine the last-year prevalence and health care utilization pattern of primary headaches at a tertiary centre . Methods . A cross-sectional study was carried out amongst staff of the Lagos State University Teaching Hospital in Lagos , Nigeria . 402 staff members were selected by simple r and om sampling and administered a detailed structured headache assessment question naire . Migraine and tension-type headache were diagnosed according to the criteria of the International Headache Society ( 2004 ) . Results . The participants comprised 168 males and 234 females . The mean age was 36.9 ± 7.9 years .  The overall headache prevalence was 39.3 % with female predominance ( P < 0.0001 ) . Tension-type headache was the most prevalent at 72.8 % and migraine at 18.9 % . Unclassifiable headache constituted 8.2 % . Migraine headache showed female preponderance ( P = 0.000 ) . 80.4 % of participants did not seek medical consultation compared with 19.6 % who did ( P = 0.000 ) . Of the latter , 83.9 % consulted the general practitioner ( GP ) , whilst 16.1 % consulted the neurologist . Conclusions . Primary headache prevalence is high in our population . It is not recognised as that requiring care by most of the staff of this tertiary health facility ; thus education is required to increase health care utilization Background . Several clinical trials have demonstrated that low doses of non‐steroidal anti‐inflammatory drugs relieve episodic tension‐type headache ( ETH ) 1 Eight double-blind , r and omized , placebo-controlled , single-dose , cross-over studies were carried out to evaluate the usefulness of testing the acute analgesic effect of drugs in out- patients with non-migrainous headache . 2 The reference compounds were either ( 1 ) aspirin , ( 2 ) a combination of aminopyrine , caffeine and butalbarbital ( Optalidon ) , and ( 3 ) a combination of ( 2 ) with dihydroergotamine ( Tonopan ) . 3 The test compounds were ( 1 ) proquazone , ( 2 ) fluproquazone and ( 3 ) and ( 4 ) , new formulations of Optalidon and Tonopan in which the aminopyrine was replaced by propyphenazone . They were all found to be active . 4 A significant , dose-response relationship was established for aspirin ( 250 , 500 and 1000 mg ) . 5 It is concluded that the non-migrainous headache model is a practical , reproducible and sensitive method for the investigation of the acute efficacy of analgesics SYNOPSIS This study aim ed at comparing the time courses of pain relief in tension headache after taking 648 mg solid ASA and after taking 648 mg effervescent ASA ( acetyl salicylic acid ) . A modified double dummy technique with both solid and effervescent placebo was used . 47 patients entered , and 33 patients took all four trial drugs . No statistically significant difference between solid and effervescent ASA could be demonstrated . ASA was significantly better than placebo although the median rating of ASA in this study was unexpectedly poor - as was the placebo response . This fact might have reflected the severely afflicted nature of a headache clinic 's population . Different pain rating scales are compared , and it is concluded that the overall ( GLOBAL ) rating is sensitive , but should not be used alone , since it may sometimes reflect less relevant factors . The power of the trial was good , but reflects the comparatively poor responsiveness to ASA ( low variance ) in this particular patient population . An advantage of the effervescent preparation in more ASA-responsive patients can not be ruled out . It is advised for future studies to recruit patients from general practice rather than from a headache-clinic population Background Previous analysis of a single data set in acute pain following third molar extraction demonstrated a strong relationship between the speed of reduction of pain intensity and overall pain relief , as well as need for additional analgesia . Methods Individual patient data analysis of a single r and omized , double-blind trial of placebo , paracetamol 1000 mg , ibuprofen sodium 400 mg and ibuprofen-poloxamer 400 mg following third molar extraction .  Visual analogue scale pain intensity ( VASPI ) and other measurements were made at baseline , every 5–45 min , and at 60 , 90 , 120 , 180 , 240 , 300 and 360 min . Results Most patients produced consistent VASPI results over time . For placebo and paracetamol , few patients achieved low VASPI scores and maintained them . For both ibuprofen formulations , VASPI scores fell rapidly during the first hour and were then typically maintained until later re-medication . Analysis of all patients showed that rapid VASPI reduction in the first hour was strongly correlated with good overall pain relief ( high total pain relief over 0–6 h ) , and with lesser need for additional analgesia within 6 h. Results for this analysis were in very good agreement with a previous analysis , validating the relationship between fast initial pain intensity reduction and overall good pain relief in this setting . Conclusions In acute pain following third molar extraction , faster acting analgesic formulations provide earlier onset of pain relief , better overall pain relief and a less frequent need for additional analgesia , indicating longer lasting pain relief A method for the evaluation of the efficacy of mild analgesic drugs in out patients with nonmigrainous headache is described . During the 3-hour drug evaluation period , patients were required to record at hourly intervals their pain intensity using both a verbal rating and a visual analog scale , their pain relief , and the occurrance of side effects . The results obtained in six studies consisted of comparisons of reference compounds aspirin ( 1000 mg ) and two analgesic combinations ( containing am 
    Output:
    
Ibuprofen 400 mg provides an important benefit in terms of being pain free at 2 hours for a small number of people with frequent episodic tension-type headache who have an acute headache with moderate or severe initial pain .
There is no information about the lesser benefit of no worse than mild pain at 2 hours