***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: The actual effectiveness rates of natural and barrier methods of family planning are lower than the theoretical ones . If couples accurately defined the limits of the fertile phase and used barriers at that time , then actual effectiveness might increase . A r and omized , controlled clinical trial was initiated to determine the effectiveness of the contraceptive sponge used only during the fertile time and to compare this with sponge use at every intercourse . Recruitment problems and discontinuation forced the early termination of this study , but qualitative information about compliance and acceptability was collected . Common sponge problems were reported as were misuses of the sponge , but problems and misuse were not related . Determination of the fertile phase was reportedly easy , but complaints of and discontinuation for inconvenience occurred . For unplanned pregnancies , contraceptive behaviors around the time of conception are presented The results of a r and omized United States study indicated that the Today contraceptive sponge was less effective than the diaphragm ( 1-year cumulative life-table rate of 17.4 versus 12.9 pregnancies per 100 women , p = 0.01 ) . However , this overall comparison is misleading . Using univariate and multivariate analyses to account for the effects of user characteristics we found parity to be the most important single determinant of effectiveness for users of the sponge , but parity was unimportant as a risk factor for pregnancy among diaphragm users . For nulliparous women the sponge was as effective as a physician-prescribed barrier method ( 13.9 for sponge , 12.8 for diaphragm , p = 0.45 ) ; however , parous women using the sponge were twice as likely to become pregnant ( 28.3 for sponge , 13.4 for diaphragm , p = 0.001 ) . The effect of parity among sponge users is consistent with the results of international studies of the contraceptive sponge 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 To investigate the effect of the contraceptive sponge on the incidence of sexually transmitted diseases , we conducted a clinical trial among a high-risk population of women in Bangkok , Thail and . Two hundred fifty-five women were r and omly assigned either to use the sponge or not and were evaluated weekly for gonorrhea and chlamydial infection . After adjustment by logistic regression for potentially confounding factors , women using the sponge were less likely to have contracted chlamydial infection ( odds ratio [ OR ] , 0.6 ; 90 % confidence interval [ CI ] , 0.4 - 1.0 ) and gonorrhea ( OR , 0.9 ; CI , 0.6 - 1.3 ) as compared with women not using the sponge . These estimates probably underestimate the degree of protection because some exposure was misclassified in this pilot phase of the study . These results are consistent with other studies indicating that spermicides protect against gonorrhea and also demonstrating protection against an organism of even greater public health concern , Chlamydia trachomatis Objective : This study was undertaken to assess the efficacy , safety and acceptability of two different-dose regimens of the Protectaid ® contraceptive sponge . Methods : The toxic effects of two forms of the new vaginal contraceptive sponge , Protectaid ® , in the cervical and vaginal tissues were studied . Both types were impregnated with F-5 gel containing different doses of nonoxynol-9 ( NX9 ; 0.5 % and 0.125 % ) . The sponge was used by 35 women aged 20 - 35 years ( mean 28.7 years ) r and omly allocated into two groups ( Group A : 0.5 % NX9 , n = 20 ; Group B : 0.125 % NX9 , n = 15 ) . Results : During a 12-month period both regimens demonstrated a 91.4 % overall contraceptive efficacy . Colposcopic examinations showed no significant cervical or vaginal lesions in either group , except for two cases at the 2-week and 3-month examinations in Group A women . In the former , inflammatory changes of little clinical significance were seen and the colposcopic appearance of the vagina was non-specific . In this case , the focal lesions were accompanied by dilated capillaries ( hyperemia ) . In the second case , degenerative inflammatory changes , with the inflammatory foci varying in shape and distribution , were observed . Cervical cultures taken 6 months after the start of treatment showed the presence of Mycoplasma hominis and C and ida albicans in one and two cases , respectively , in Group A. In Group B , cervical cultures taken at 3 months showed Gardnerella vaginalis and β-hemolytic streptococci group B in one and two cases , respectively . Conclusion : The potent spermicidal and protective properties of this new contraceptive sponge may be of benefit to the sexually active female . Since the sponge was very well accepted by both the study participants and their sexual partners , it can be considered as a valuable barrier method A comparative trial was conducted in the United States to compare the Today contraceptive sponge and the diaphragm used with spermicide . Subjects were r and omly assigned to contraceptive methods and were followed up for 1 year . None of the subjects were previous sponge users , but about 30 % were previous diaphragm users . The overall cumulative 1-year life-table pregnancy rate was higher for sponge users compared to diaphragm users . No serious side effects occurred with either product . The discontinuation rates for allergic-type reactions and discomfort were higher for sponge users . Similar rates of method -related complaints and discontinuation rates for personal and product-related reasons suggest there were no differences in the acceptability of the two products . In this trial , the allowable use time for the sponge was 2 days . The sponge is now recommended for 1-day use . The overall results of the study indicate the sponge to be a safe and acceptable method of contraception with an effectiveness rate in the range of that for other vaginal contraceptives Users of the Today contraceptive sponge who participated in a comparative trial of the sponge and diaphragm  were followed up for an additional year . There were no serious adverse effects attributable to sponge use during the second year of use . The second year life-table pregnancy rate for  sponge  users was significantly lower ( p<0.05 ) than the first year rate . The pregnancy rates for first time sponge and diaphragm users were similar ( p>0.10 ) and both rates improved with increasing user experience . ResuméLes utilisatrices d'éponges contraceptives Today qui ont participé à des essais destinés à faire une comparaison entre les éponges et les diaphragmes ont été suivies pendant une année supplémentaire . Aucun effet défavorable grave qui puisse être attribué à l'usage des éponges n'a été constaté au cours de la seconde année . Les taux de grossesses chez les utilisatrices d'éponges ont été significativement plus faibles ( p<0,05 ) pour la seconde année que pour la première ( calculé par la méthode des tables de survie ) . Les taux de grossesses étaient similaires chez celles qui utilisaient l'éponge et le diaphragme pour la première fois ( p>0,10 ) et ces taux se sont améliorés dans un cas comme dans l'autre à mesure que ces femmes en acquéraient l'expérience . ResumenA usuarias de la esponja anticonceptiva Today que participaron en una prueba comparativa de la esponja y el diafragma , se les hizo seguimiento durante un año adicional . Durante el segundo año de uso no se produjeron effectos adversos serios atribuibles a la esponja . Los embarazos que ocurrieron durante el segundo año de uso , analizados por la tabla de vida , fueron significativamente más bajos que los del primer año ( p<0.05 ) . Las tasas de embarazo para usuarias por primera vez de la esponja y del diafragma fueron similares ( p>0,10 ) y ambas tasas mejoraron con el aumento de experiencia en las usuarias This paper describes the results from a r and omized clinical trial comparing the Collatex vaginal contraceptive sponge ( a predecessor of the Today sponge ) and Neo Sampoon foaming vaginal contraceptive tablets ; the trial was conducted from 1979 to 1983 in four centers located in three countries ( two in Yugoslavia and one each in Taiwan and Bangladesh ) . The sponge was associated with more insertion and retention problems than the tablet , especially in the two Asian centers . More Neo Sampoon users complained of a burning or stinging sensation . This complaint , however , seemed to be well-tolerated and was not a frequent reason for irregular use and /or discontinuation of use of the tablets . Clinical ly significant medical complications were rarely reported for either method . Sponge users were more likely to report irregular use than tablet users , primarily due to inconvenience of use . Rates of discontinuation at six months of use were also consistently higher among  sponge users than Neo Sampoon users in the four centers . Life-table pregnancy rates at 12 months of use ranged from 3.8 to 18.2 per 100  sponge users and 6.2 to 29.9 per 100 Neo Sampoon users , based on data from the two Yugoslavian centers and the Taiwan center ( data from the Bangladesh center were excluded from analysis of pregnancy rates ) . Practical implication s of these findings are discussed Neo Sampoon , a foaming vaginal tablet containing 60 mg of the spermicide menfegol , and the Collatex sponge ( now marketed in the United States as the Today sponge ) , a domeshaped polyurethane device that contains 1 g of nonoxynol-9 , were compared in terms of effectiveness , safety , and acceptability . Both methods were new to the Maribor General Hospital , Yugoslavia , where the trial was conducted among 450 volunteers r and omly assigned to one of the two methods . At 12 months , the life-table pregnancy rate per 100 women for the Neo Sampoon group was 12.8 , compared with a rate of 10.4 among the sponge users ( P>.10 ) . After pregnancy , the second most frequent reason for termination was discomfort , with a 12-month termination rate due to this cause of 6.9 per 100 women in the Neo Sampoon group and 6.2 in the sponge group . Although fewer than a quarter of the volunteers had any experience with barrier methods before this trial , the life-table continuation rate was high in both groups , with more than 70 % using their assigned method for the full 12 months . Also , upon conclusion of the study , 41 % of the volunteers chose another barrier contraceptive method . Although the effectiveness of the sponge and Neo Sampoon is not comparable to that of the pill or IUD , both vaginal methods appear to be safe and acceptable additions to the range of contraceptive choices To investigate the effect of the nonoxynol 9-impregnated contraceptive sponge on the incidence of chlamydial infection , gonorrhea , and c and idiasis , we conducted a r and omized comparative study among high-risk women in Bangkok , Thail and . The first ( parallel ) portion of the study covered 434 woman-weeks among sponge users and 494 woman-weeks among nonusers . As compared with women not using the sponge , sponge users were found to be less likely to become infected with chlamydia ( relative rate , 0.67 ; 95 % confidence interval , 0.42 to 1.07 ) and gonorrhea ( relative rate , 0.31 [ 0.16 to 0.60 ] ) but more likely to become infected with C and ida ( relative rate , 2.76 [ 0.96 to 7.98 ] ) . Women who continued in the study were crossed over to the alternate group , with former nonusers starting to employ the sponge and vice versa . The results of this second phase were similar to those of the larger parallel study . Overall , these results suggest that women using the sponge are protected against the two most common sexually transmitted pathogens , which are also those with the most serious health consequences . However , women using the sponge should be advised they may have an increased likelihood of a vaginal infection with C and ida CONTEXT Nonoxynol-9 has been suggested as a vaginal microbicide to protect against common sexually transmitted infections . O 
    Output:
    
REVIEW ER 'S CONCLUSIONS The sponge was less effective than the diaphragm in preventing pregnancy .
Discontinuation rates were higher at 12 months as well .