***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: Postal health surveys in the general population can provide important information to assist with planning and service provision . 1 High response rates are needed to ensure validity and to minimize costs from following-up non-responders . 2 Only a small number of studies have examined methods to increase response rates in postal surveys . Using a post-office stamp rather than a prepaid business reply envelope may seem more personal and encourage participants to return the question naire . However , results from trials evaluating this are inconsistent and limited to health professionals in North America . 3–5 Consequently there is little evidence to inform the choice of reply envelopes in postal surveys of the general UK population . This was determined in the current study . Methods The sample consisted of 633 adults r and omly selected from a health authority register in the north west of Engl and . A computer-generated r and omization list , stratifying on sex and age ( 18–45 , 46–64 , у65 years ) was used to allocate participants to receive one of two types of reply envelopes , both printed with the return address . One group ( POS ) received a reply envelope with a first-class post-office stamp , while the second group ( PPB ) received a prepaid business-franked envelope to return their health question naire . The initial mail-out included the 16-page health question naire , a personalized letter from the Director of Public Health and one of the two return envelopes . Question naires were sent out in March 2001 and non-responders were sent a reminder postcard 10 days later . The primary outcome was the difference in response rates between the two types of reply envelopes , after follow-up reminders had been sent measured at 4 weeks after posting the survey . The χ 2 test was used to examine statistical significance . Approval was obtained for the study from the Local Research Ethics Committee.2 % ) question naires were returned within 10 days , from the two allocation groups , respectively . After sending reminders to the 182 non-responders in the POS group and 195 in the PPB group ( excluding 6 and 4 participants respectively later found to be not living at that address ) , the return rate increased to 182 ( 58.7 % ) and 179 ( 57.2 % ) in the two groups . This difference of 1.5 % between the two groups is unlikely to be important and was not statistically significant ( χ 2 = 0.08 , P = 0.77 ) . No important difference was observed in return rates between the POS and the PPB group for men or women and across three age groups . However , return rates BACKGROUND Patient surveys are becoming increasingly common and already are an obligatory activity to qualify for a Better Practice Program Grant . Strategies to increase return rates remain unevaluated in Australian general practice . AIM To evaluate the effectiveness of an instant lottery ticket as a response-aiding technique in patient surveys . METHOD A r and om sample of adult patients was selected from an age-sex-disease register , stratified by sex and r and omised to receive an instant lottery ticket with the self-administered question naire mailed out in December 1994 . RESULTS There was no significant difference by group either for women ( P = 0.68 ) , men ( P = 0.88 ) or both sexes combined ( P = 0.68 ) . However , irrespective of inclusion of the lottery ticket , men were significantly less likely to return question naires than women ( P = 0.02 ) . CONCLUSIONS Instant lottery tickets do not increase return rates to question naires and are not recommended . Other strategies need to be tested , particularly to involve male patients in general practice research Study objective : To assess the effectiveness of a telephone reminder in increasing responses to postal surveys and to calculate the differential costs per completed question naire . Design : R and omised controlled trial . Setting : Australian university and rehabilitation medicine practice . Participants : The trial was conducted in 1999 among the 143 non-respondents to a question naire about work related neck and upper body disorders . The question naire was sent to two Australian female sample s : 200 office workers ( Sample A ) and 92 former rehabilitation medicine patients ( Sample B ) . A reminder letter , another copy of the question naire and a final letter were sent at two week intervals . Half of the non-respondents within each sample were r and omly selected to receive a telephone reminder just after the second mailout of the question naire . All direct costs were calculated . Main results : Responses were significantly higher among those who received the telephone reminder intervention ( relative risk 2.54 , 95 % confidence intervals 1.43 to 4.52 ) . Analysed by intention to phone , 47 % of non-respondents in Sample A and 38 % in Sample B returned a complete question naire after the intervention , compared with 21 % and 10 % , respectively , in the control groups . For the 112 women ( combined sample s ) who returned completed question naires before r and omisation , the average cost per respondent was AUD14 . There was a higher total cost for the intervention groups ( AUD851 versus AUD386 for controls ) , but the significantly higher number of additional completed responses ( 31 versus 12 ) result ed in a 15 % lower marginal cost per completed question naire in those groups . Conclusion : Telephone reminders are cost effective in improving responses to postal surveys Proper r and omisation means little if investigators can not include all r and omised participants in the primary analysis . Participants might ignore follow-up , leave town , or take aspartame when instructed to take aspirin . Exclusions before r and omisation do not bias the treatment comparison , but they can hurt generalisability . Eligibility criteria for a trial should be clear , specific , and applied before r and omisation . Readers should assess whether any of the criteria make the trial sample atypical or unrepresentative of the people in which they are interested . In principle , assessment of exclusions after r and omisation is simple : none are allowed . For the primary analysis , all participants enrolled should be included and analysed as part of the original group assigned ( an intent-to-treat analysis ) . In reality , however , losses frequently occur . Investigators should , therefore , commit adequate re sources to develop and implement procedures to maximise retention of participants . Moreover , research ers should provide clear , explicit information on the progress of all r and omised participants through the trial by use of , for instance , a trial profile . Investigators can also do secondary analyses on , for instance , per- protocol or as-treated participants . Such analyses should be described as secondary and non-r and omised comparisons . Mish and ling of exclusions causes serious method ological difficulties . Unfortunately , some explanations for mish and ling exclusions intuitively appeal to readers , disguising the seriousness of the issues . Creative mismanagement of exclusions can undermine trial validity BACKGROUND A range of factors have been shown to affect the response rate to mailed question naires , but particular strategies to improve patients ' response in trials conducted in general practice require further study . METHODS Non-responders in a larger trial were r and omized to receive a telephone or recorded delivery reminder on the third contact . The cost of administration of each method was estimated . RESULTS Significantly more patients returned completed question naires when sent question naires by recorded delivery , although the cost per patient contacted was nearly three times more than for contact by telephone . CONCLUSION Our study indicates that sending reminders by recorded delivery , although more expensive , is more effective than telephone reminders for recruiting patients to a study in general practice using research question naires Objective : To assess whether length of question naire affects response rates . Methods : A quasi-r and omised trial of women aged 70 years and over in a general practice in Engl and .  Three question naires of different lengths : a clinical question naire ( four pages ) ; the same question naire plus the EuroQol ( five pages ) ; the same question naire plus the SF-12 ( seven pages ) . The impact of length on the proportion of returned question naires and item completion rates was assessed . Results : In total , 847 question naires were mailed ;  response rates were 49 % , 49 % and 40 % to the short , medium and long question naires , respectively . This difference was statistically significant when the short question naire was compared against the longest instrument ( 9 % difference ; 95 % confidence interval ( CI ) of difference=0.3 % to 16.6 % ) . Item completion rates for the clinical question naire did not differ . Respondents did not differ in age or self-reported health status between the three groups . Conclusions : Increasing the length of a question naire from five to seven pages reduces response rates from women aged 70 years and over . However , lengthening a question naire does not seem to affect the quality of responses to questions near the front of the question naire PURPOSE To investigate the impact on subject response of an information brochure and cash incentives included with mailed question naires in case-control studies . METHODS A r and omized trial was carried out within a case-control study investigating cancer in the Province of Ontario . Brochures were included with half of the mailed question naires sent to 7487 cases and 2561 controls . Controls were also sent cash incentives of $ 2 , $ 5 , or no money . RESULTS With the brochure , response changed from 75.0 % to 75.8 % in cases , and from 70.3 % to 71.1 % in controls . Adjusting for differences in age , residence , sex , and cancer site/status , the change was 0.2 % [ 95 % confidence interval ( CI ) = -1.7 - 2.1 ] in cases , and 0.6 % ( 95 % CI = -3.1 - 4.3 ) in controls . The $ 2 and $ 5 incentives increased overall response in controls from 61.9 % to 72.8 % and 77.2 % , respectively , i.e. , by 10.9 % ( 95 % CI = 6.1 - 15.6 ) and 15.1 % ( 95 % CI = 10.4 - 19.7 ) , after adjustment . This effect was largely confined to urban areas ( for $ 2 and $ 5 , respectively : 5.5 % and 14.2 % in Toronto , 15.3 % and 20.4 % in other urban areas vs. 2.7 % and 1.0 % in rural areas ; p = 0.02 ) . Response time showed little or no improvement when the brochure was included , but was markedly reduced for both the $ 2 and $ 5 incentives . CONCLUSIONS Cash incentives can improve subject response in epidemiologic studies , whereas information brochures do not appear to have an effect Mail surveys have been used to follow-up early participants in a Canadian breast cancer prevention trial . To minimize non-response bias , we undertook a r and omized study of two postal strategies , of which one was our usual procedure and the other was a systematic application , known as the total design method ( TDM ) and described by Dillman . The response rates to the two methods were 62 and 88 % respectively . The TDM is a practical , cost-efficient approach to reducing non-response bias in postal surveys and as such has an important role in epidemiological research which involves healthy participants Most systematic review s rely substantially on the assessment of the method ological quality of the individual trials . The aim of this study was to obtain consensus among experts about a set of generic core items for quality assessment of r and omized clinical trials ( RCTs ) . The invited participants were experts in the field of quality assessment of RCTs . The initial item pool contained all items from existing criteria lists . Subsequently , we reduced the number of items by using the Delphi consensus technique . Each Delphi round comprised a question naire , an analysis , and a feedback report . The feedback report included staff team decisions made on the basis of the analysis and their justification . A total of 33 international experts agreed to participate , of whom 21 completed all question naires . The initial item pool of 206 items was reduced to 9 items in three Delphi rounds . The final criteria list ( the Delphi list ) was satisfactory to all participants . It is a starting point on the way to a minimum reference st and ard for RCTs on many different research topics . This list is not intended to replace , but rather to be used alongside , existing criteria lists Mailed surveys are widely used to collect epidemiological and health service data on cancer population s. Nonresponse can threaten the validity of surveys and various strategies , including the enclosure of modest incentives , are often used to increase response rates . A study was undertaken to determine whether response rate to a mailed survey differed with provision of immediate versus delayed incentives . A six-page mailed survey to ascertain dietary supplement use was sent to 1402 men who had been diagnosed with prostate cancer . Subjects were block r and omized into two groups based on age ( ≤65 years versus > 65 years ) , race ( white versus nonwhite ) , and disease status ( locoregional versus distant ) . One group received a 30-min prepaid phone card concurrently with their blank survey ( unconditional incentive ) , whereas the other group received the incentive only on receipt of their completed survey ( conditional incentive ) . A 60 % overall response rate was achieved , and no differences in response rates were noted between conditional and unconditional incentive groups ( overall , as well as within defined age , race , and disease-defined strata ) . Nonwhites , however , were significantly less likely to respond than whites ( P < 0.0001 ) . In conclusion , acceptable response rates to a mailed survey can be achieved in a general population of cancer survivors using modest incentives . Given no differences in response rates using conditional versus unconditional incentives , the decision to provide immediate versus delayed incentives is one that should be considered on a study -specific basis , and a decision based primarily on cost . Other means , however , appear necessary to achieve acceptable response rates among minority group cancer survivors Maximizing the response rate of self-administered question naires is key in survey research . We aim ed to evaluate the effects of lottery incentive and length of question naire on health survey response rates when used in isolation or combined . A r and om sample of 440 residents in Western Sydney , Australia was r and omly allocated to four equal groups to receive or not receive an instant lottery ticket and a long ( seven page ) or short ( one 
    Output:
    
No evidence was found that incentives , re-ordering of questions or including an information brochure with the question naire confer any additional advantage .
Conclusion Implementing repeat mailing strategies and /or telephone reminders may improve response to postal question naires in health care research .
Making the question naire shorter may also improve response rates .
There is a lack of evidence to suggest that incentives are useful .