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K F Schulz

Publications and source records attributed to K F Schulz.

At least 37 records · Page 2Linked to original sources
PubMed2003

Combined hormonal versus nonhormonal versus progestin-only contraception in lactation.

BACKGROUND: Contraception for women who are breastfeeding is a public health issue of global importance. Each year over 100 million women make decisions about beginning or resuming contraception after childbirth. These decisions include both the choice of contraceptive method and the time at which its use begins, both of which continue to be debated by experts. Choices of contraception may be limited for lactating women due to concerns about hormonal effects on quality and quantity of milk, passage of hormones to the infant, and infant growth. Ideally, the contraceptive method chosen should not interfere with lactation. Additionally, because the return of menstruation and ovulation can be unpredictable in breastfeeding women, the timing of contraception initiation is important. OBJECTIVES: To determine the effect of combined oral contraceptives and progestin-only contraceptives on lactation. The a priori hypothesis is that combined oral contraception impairs lactation, making it less appropriate than progestin-only or nonhormonal contraception for breastfeeding women. SEARCH STRATEGY: We used PUBMED, POPLINE, EMBASE, LILACS, and Cochrane Controlled Trials Register computer searches, supplemented by review articles and contact with investigators. SELECTION CRITERIA: We sought all randomized controlled trials, reported in any language, that included any form of hormonal contraception compared with another form of hormonal contraception, nonhormonal contraception, or placebo during lactation. Hormonal contraception could include combined oral or injectable contraceptives, progestin-only oral or injectable contraceptives, hormonal implants, or hormonal intrauterine devices. Study participants included breastfeeding women of any age or parity who desired contraception. DATA COLLECTION AND ANALYSIS: We evaluated the methodological quality of each report and sought to identify duplicate reporting of data from multicenter trials. We abstracted data onto data collection forms. Principal outcome measures included quantity of milk; biochemical analysis of milk composition; initiation, maintenance and duration of lactation; infant growth; efficacy of contraceptive method while breastfeeding; and timing of contraception initiation and its effects on lactation. Because the trials did not have uniform interventions, often lacked quantifiable outcomes, and had poor methodological quality, we could not aggregate the data in a meta-analyses. MAIN RESULTS: Seven reports from five randomized controlled trials met our inclusion criteria. Most of the five trials did not specify their method used to generate a random sequence, method of allocation concealment, blinding of treatments, or use of an intention-to-treat analysis. Additionally, high loss to follow-up rates invalidated at least two studies. The findings from two reports comparing oral contraceptives to placebo during lactation were conflicting. Another trial found no inhibitory effects on lactation from progestin-only contraceptives. Finally, the WHO trial found no effect of progestin-only contraceptives on lactation but a decline in breast milk volume from combination contraceptives during lactation. High loss to follow-up rates, however, undermine the credibility of the WHO trial. No significant differences in infant growth or weight appeared in any of the included trials as a result of the use of hormonal contraception during lactation. REVIEWER'S CONCLUSIONS: Evidence from randomized controlled trials on the effect of hormonal contraceptives during lactation is limited and of poor quality; results should be interpreted with caution. The existing randomized controlled trials are insufficient to establish an effect of hormonal contraception, if any, on milk quality and quantity. Evidence is inadequate to make recommendations regarding hormonal contraceptive use for lactating women. At least one properly conducted randomized controlled trial of adequate size is urgently needed to address this question.

Contraceptives, Oral, Combined↗
PubMed2003

Combination contraceptives: effects on weight.

BACKGROUND: Weight gain is often attributed as a side effect of combination hormonal contraceptive, and many women and clinicians believe that an association exists. Concern about weight gain can limit the use of this highly effective method of contraception by deterring the initiation of its use and causing early discontinuation among users. Nevertheless, a causal relationship between combination contraceptives and weight gain has not been established. OBJECTIVES: The aim of the review was to evaluate the association between combination contraceptive use and changes in weight. SEARCH STRATEGY: We searched the computerized databases MEDLINE, Popline, CENTRAL, EMBASE, and LILACS for studies of combination contraceptives. We also wrote to known investigators and manufacturers to request information about other published or unpublished trials not discovered in our search. SELECTION CRITERIA: All English-language, randomized controlled trials at least three treatment cycles in duration that compared a combination contraceptive to a placebo or with a combination contraceptive that differed in drug, dosage, regimen, and/or study length were eligible. DATA COLLECTION AND ANALYSIS: All titles and abstracts located in the literature searches were assessed. Data were entered and analyzed with RevMan 4.1, and a second reviewer verified the data entered. Depending on the data available, the weighted mean difference using a fixed effects model with 95% confidence intervals was calculated for the mean change in weight between baseline and post-treatment measurements or the Peto odds ratio with 95% confidence intervals was calculated using the proportion of women who gained or lost more than a specified amount of weight. MAIN RESULTS: The three placebo-controlled, randomized trials did not find evidence supporting a causal association between combination oral contraceptives or a combination skin patch and weight gain. Most comparisons of different combination contraceptives showed no substantial difference in weight. In addition, discontinuation of combination contraceptives because of weight gain did not differ between groups where this was studied. REVIEWER'S CONCLUSIONS: Available evidence is insufficient to determine the effect of combination contraceptives on weight, but no large effect is evident.

Body Weight↗
PubMed2003

Nonlatex vs. latex male condoms for contraception: a systematic review of randomized controlled trials.

This systematic review sought to evaluate nonlatex male condoms in comparison with latex condoms in terms of contraceptive efficacy, breakage, slippage, safety and user preferences. We searched computerized databases and contacted manufactures and investigators to find randomized controlled trials of nonlatex vs. latex male condoms. Two reviewers independently abstracted data from the 10 identified trials. While the eZ. on condom did not protect against pregnancy as well as its latex comparison condom, no differences were found in typical-use efficacy between the Avanti and the Standard Tactylon and their latex counterparts. Nonlatex condoms were associated with higher rates of clinical breakage than their latex comparisons, with statistically significant odds ratios of clinical breakage ranging from 2.6 (95% confidence interval [CI]: 1.6-4.3) to 5.0 (95% CI: 3.6-6.8). Few adverse events were reported. Substantial proportions of participants reported preferences for the nonlatex condoms. Despite higher rates of clinical breakage, nonlatex condoms still provide an acceptable alternative for those with allergies, sensitivities or preferences that might prevent the consistent use of latex condoms. The contraceptive efficacy of nonlatex condoms requires more research.

Condoms↗
PubMed2003

Sponge versus diaphragm for contraception: a Cochrane review.

The contraceptive vaginal sponge was developed as an alternative to the contraceptive diaphragm. Unlike the diaphragm, the sponge can be used for more than one coital act within 24 h without the insertion of additional spermicide, and it does not require fitting or a prescription from a physician. We conducted a systematic review of randomized controlled trials that compared the vaginal contraceptive sponge with the diaphragm used with a spermicide in order to evaluate the efficacy and continuation rates of the two devices. The sponge was statistically significantly less effective in preventing overall pregnancy than was the diaphragm in the two trials that met our inclusion criteria. The 12-month cumulative life table termination rates per 100 women for overall pregnancy were 17.4 for the sponge versus 12.8 for the diaphragm in the larger US trial, and 24.5 for the sponge and 10.9 for the diaphragm in the UK trial. Similarly, discontinuation rates at 12 months were higher with the sponge than with the diaphragm [odds ratio 1.3; 95% confidence interval (CI) 1.1-1.6]. Allergic-type reactions were more common with the sponge in both trials, although the frequency of discontinuation for discomfort differed in the two trials. Other randomized controlled trials will be needed to resolve the role of spermicides in preventing sexually transmitted infections or in causing adverse effects.

Contraceptive Devices, Female↗
PubMed2003

Hormonal contraception during lactation. systematic review of randomized controlled trials.

Contraception choices may be limited for lactating women due to concerns about hormonal effects on quality and quantity of milk, passage of hormones to the infant and infant growth. We conducted a systematic review of randomized controlled trials to determine the effect of hormonal contraception on lactation. We sought all randomized controlled trials, reported in any language, that included any form of hormonal contraception compared with another form of hormonal contraception, nonhormonal contraception or placebo during lactation. Seven reports from five randomized controlled trials met the inclusion criteria. Most of the five trials did not specify their method used to generate a random sequence, method of allocation concealment, blinding of treatments or use of an intention-to-treat analysis. Additionally, high loss-to-follow-up rates invalidated at least two trials. The findings from two trials comparing oral contraceptives to placebo during lactation were conflicting. Another trial found no inhibitory effects on lactation from progestin-only contraceptives. Finally, the World Health Organization trial found a statistically significant decline in breast milk volume in women using combined oral contraceptives compared to women using progestin-only pills. However, infant growth for the two groups did not differ. The limited evidence from randomized controlled trials on the effect of hormonal contraceptives during lactation is of poor quality and insufficient to establish an effect of hormonal contraception, if any, on milk quality and quantity. At least one properly conducted randomized controlled trial of adequate size is urgently needed to make recommendations regarding hormonal contraceptive use for lactating women.

Contraceptives, Oral, Combined↗
PubMed2002

Sponge versus diaphragm for contraception.

BACKGROUND: The contraceptive vaginal sponge was developed as an alternative to the contraceptive diaphragm. The sponge, made of polyurethane impregnated with nonoxynol-9 (1g), releases 125 mg of the spermicide over 24 h of use. Unlike the diaphragm, the sponge can be used for more than one coital act within 24 h without the insertion of additional spermicide, and the sponge does not require fitting or a prescription from a physician. How the sponge compares with the diaphragm in terms of efficacy and continuation is not clear. OBJECTIVES: To compare the efficacy and continuation rates of the sponge compared with the diaphragm (used with nonoxynol-9 as a spermicide). Our a priori hypothesis was that the sponge would have a higher failure rate and higher discontinuation rates than the diaphragm. SEARCH STRATEGY: We searched the computerized databases MEDLINE, EMBASE, Popline, LILACS, and the Cochrane Controlled Trials Register. In addition, we searched the reference lists of all potentially relevant articles and book chapters. We also contacted investigators involved with both trials identified to seek other published or unpublished trials. SELECTION CRITERIA: We included randomized controlled trials comparing the vaginal contraceptive sponge (Today; Collatex) with any diaphragm used with nonoxynol-9 to prevent pregnancy. DATA COLLECTION AND ANALYSIS: We examined the studies identified through the literature searches for possible inclusion and evaluated their methodological quality using the Cochrane guidelines. We contacted an author involved with both published trials for supplementary information about randomization and allocation concealment. We entered data into RevMan 4.1 and calculated Peto odds ratios for overall pregnancy and 12-month discontinuation using numbers of women as the denominator. We also abstracted 12-month cumulative life-table ratios for these same outcomes, but were unable to aggregate these data. MAIN RESULTS: The sponge was statistically significantly less effective in both trials in preventing overall pregnancy than was the diaphragm. The 12-month cumulative life-table termination rates per 100 women for overall pregnancy were 17.4 for the sponge versus 12.8 for the diaphragm in the larger U.S. trial and 24.5 for the sponge and 10.9 for the diaphragm in the U.K. trial. Similarly, discontinuation rates at 12 months were higher with the sponge than with the diaphragm (odds ratio 1.3; 95% CI 1.1-1.6). Allergic-type reactions were more common with the sponge in both trials, although the frequency of discontinuation for discomfort differed in the two trials. REVIEWER'S CONCLUSIONS: The sponge was less effective than the diaphragm in preventing pregnancy. Discontinuation rates were higher at 12 months as well. Other randomized controlled trials will be needed to resolve the role of spermicides in preventing sexually transmitted infections or in causing adverse effects.

Contraceptive Devices, Female↗
PubMed2002

Cervical cap versus diaphragm for contraception.

BACKGROUND: The cervical cap and the diaphragm are vaginal barrier contraceptive methods that prevent pregnancy by covering the cervix. The two devices also act as a reservoir for spermicide. The cervical cap is smaller and can remain in place longer than the diaphragm. Two types of cervical caps, the Prentif cap and the FemCap, have been compared to the diaphragm in randomized controlled trials. OBJECTIVES: The review seeks to evaluate the contraceptive efficacy, safety, discontinuation, and acceptability of the cervical cap with that of the diaphragm. SEARCH STRATEGY: We searched MEDLINE, Popline, Cochrane Controlled Trials Register, EMBASE, and LILACS for randomized controlled trials of cervical caps, and we reviewed the references of the included publications. Also, we wrote to the manufacturers and known investigators to request information about any other published or unpublished trials not found in our search. SELECTION CRITERIA: All randomized controlled trials in any language comparing a cervical cap with a diaphragm were eligible for inclusion. DATA COLLECTION AND ANALYSIS: All titles and abstracts located in the literature searches were assessed, and articles identified for inclusion were independently abstracted by two reviewers. Data were entered and analyzed with RevMan 4.1, and a second reviewer verified the data entered. Outcome measures include contraceptive efficacy, safety, discontinuation, and acceptability. Outcomes were calculated as Peto odds ratios with 95 percent confidence intervals using women as the denominators. Life-table and Kaplan-Meier cumulative rate ratios for selected measures were also presented in "Additional Tables." MAIN RESULTS: The Prentif cap was comparable to the diaphragm in preventing pregnancy, but the FemCap was not as effective in preventing pregnancy as its comparison diaphragm. The curves for the life-table cumulative pregnancy rates through 24 months for the Prentif cap and the diaphragm were not statistically significantly different (p-value of 0.39). However, the six-month Kaplan-Meier cumulative pregnancy rates for the FemCap and the diaphragm did not meet the a priori definition of clinical equivalence. The Prentif cap had a higher proportion of Class I to Class III cervical cytologic conversions at the three-month visit than the diaphragm; the odds ratio was 2.3 (95% CI, 1.0-5.1). The FemCap trial did not find differences in Papanicolaou smear results between the cap and diaphragm groups. Prentif cap users had a lower odds ratio of vaginal ulcerations or lacerations (0.3; 95% CI, 0.1-0.7) than diaphragm users. FemCap users had a higher odds ratio of blood in the device on removal (2.3; 95% CI, 1.3-4.1), but a lower odds ratio of urinary tract infections (0.6; 95% CI, 0.4-1.0) than those in the diaphragm group. In the FemCap trial, similar proportions of women reported liking their assigned device "somewhat" or "a lot" at the two-week interview. However, FemCap users were less likely than the diaphragm users to state that they were "probably" or "definitely" likely to use the device alone after completing the trial (odds ratio of 0.5; 95% CI, 0.3-0.7) or that they would recommend it to a friend (odds ratio of 0.5; 95% CI, 0.3-0.8). REVIEWER'S CONCLUSIONS: The Prentif cap was as effective as its comparison diaphragm in preventing pregnancy, but the FemCap was not. Both cervical caps appear to be medically safe.

Adult↗
PubMed2001

The CONSORT statement: revised recommendations for improving the quality of reports of parallel group randomized trials.

To comprehend the results of a randomized controlled trial (RCT), readers must understand its design, conduct, analysis and interpretation. That goal can only be achieved through complete transparency from authors. Despite several decades of educational efforts, the reporting of RCTs needs improvement. Investigators and editors developed the original CONSORT (Consolidated Standards of Reporting Trials) statement to help authors improve reporting by using a checklist and flow diagram. The revised CONSORT statement presented in this paper incorporates new evidence and addresses some criticisms of the original statement.The checklist items pertain to the content of the Title, Abstract, Introduction, Methods, Results and Discussion. The revised checklist includes 22-items selected because empirical evidence indicates that not reporting the information is associated with biasedestimates of treatment effect or the information is essential to judge the reliability or relevance of the findings. We intended the flow diagram to depict the passage of participants through an RCT. The revised flow diagram depicts information from four stages of a trial (enrollment, intervention allocation, follow-up, and analysis). The diagram explicitly includes the number of participants, for each intervention group, included in the primary data analysis. Inclusion of these numbers allows the reader to judge whether the authors have performed an intention-to-treat analysis.In sum, the CONSORT statement is intended to improve the reporting of an RCT, enabling readers to understand a trial's conduct and to assess the validity of its results.

Humans↗
PubMed2001

The CONSORT statement: revised recommendations for improving the quality of reports of parallel-group randomized trials.

To comprehend the results of a randomized controlled trial (RCT), readers must understand its design, conduct, analysis, and interpretation. That goal can be achieved only through complete transparency from authors. Despite several decades of educational efforts, the reporting of RCTs needs improvement. Investigators and editors developed the original CONSORT (Consolidated Standards of Reporting Trials) statement to help authors improve reporting by using a checklist and flow diagram. The revised CONSORT statement presented in this article incorporates new evidence and addresses some criticisms of the original statement. The checklist items pertain to the content of the Title, Abstract, Introduction, Methods, Results, and Comment. The revised checklist includes 22 items selected because empirical evidence indicates that not reporting the information is associated with biased estimates of treatment effect or because the information is essential to judge the reliability or relevance of the findings. We intended the flow diagram to depict the passage of participants through an RCT. The revised flow diagram depicts information from 4 stages of a trial (enrollment, intervention allocation, follow-up, and analysis). The diagram explicitly includes the number of participants, according to each intervention group, included in the primary data analysis. Inclusion of these numbers allows the reader to judge whether the authors have performed an intention-to-treat analysis. In sum, the CONSORT statement is intended to improve the reporting of an RCT, enabling readers to understand a trial's conduct and to assess the validity of its results.

Publishing↗
PubMed2001

The CONSORT statement: revised recommendations for improving the quality of reports of parallel-group randomized trials.

To comprehend the results of a randomized, controlled trial (RCT), readers must understand its design, conduct, analysis, and interpretation. That goal can be achieved only through complete transparency from authors. Despite several decades of educational efforts, the reporting of RCTs needs improvement. Investigators and editors developed the original CONSORT (Con solidated S tandards o f R eporting T rials) statement to help authors improve reporting by using a checklist and flow diagram. The revised CONSORT statement presented in this paper incorporates new evidence and addresses some criticisms of the original statement. The checklist items pertain to the content of the Title, Abstract, Introduction, Methods, Results, and Discussion. The revised checklist includes 22 items selected because empirical evidence indicates that not reporting the information is associated with biased estimates of treatment effect or because the information is essential to judge the reliability or relevance of the findings. We intended the flow diagram to depict the passage of participants through an RCT. The revised flow diagram depicts information from four stages of a trial (enrollment, intervention allocation, follow-up, and analysis). The diagram explicitly includes the number of participants, for each intervention group, that are included in the primary data analysis. Inclusion of these numbers allows the reader to judge whether the authors have performed an intention-to-treat analysis. In sum, the CONSORT statement is intended to improve the reporting of an RCT, enabling readers to understand a trial's conduct and to assess the validity of its results.

Algorithms↗
PubMed2001

The revised CONSORT statement for reporting randomized trials: explanation and elaboration.

Overwhelming evidence now indicates that the quality of reporting of randomized, controlled trials (RCTs) is less than optimal. Recent methodologic analyses indicate that inadequate reporting and design are associated with biased estimates of treatment effects. Such systematic error is seriously damaging to RCTs, which boast the elimination of systematic error as their primary hallmark. Systematic error in RCTs reflects poor science, and poor science threatens proper ethical standards. A group of scientists and editors developed the CONSORT (Con solidated S tandards o f R eporting T rials) statement to improve the quality of reporting of RCTs. The statement consists of a checklist and flow diagram that authors can use for reporting an RCT. Many leading medical journals and major international editorial groups have adopted the CONSORT statement. The CONSORT statement facilitates critical appraisal and interpretation of RCTs by providing guidance to authors about how to improve the reporting of their trials. This explanatory and elaboration document is intended to enhance the use, understanding, and dissemination of the CONSORT statement. The meaning and rationale for each checklist item are presented. For most items, at least one published example of good reporting and, where possible, references to relevant empirical studies are provided. Several examples of flow diagrams are included. The CONSORT statement, this explanatory and elaboration document, and the associated Web site ( http://www.consort-statement.org ) should be helpful resources to improve reporting of randomized trials. Throughout the text, terms marked with an asterisk are defined at end of text.

Algorithms↗
PubMed2001

The CONSORT statement: revised recommendations for improving the quality of reports of parallel-group randomised trials.

To comprehend the results of a randomised controlled trial (RCT), readers must understand its design, conduct, analysis, and interpretation. That goal can be achieved only through total transparency from authors. Despite several decades of educational efforts, the reporting of RCTs needs improvement. Investigators and editors developed the original CONSORT (Consolidated Standards of Reporting Trials) statement to help authors improve reporting by use of a checklist and flow diagram. The revised CONSORT statement presented here incorporates new evidence and addresses some criticisms of the original statement. The checklist items pertain to the content of the Title, Abstract, Introduction, Methods, Results, and Discussion. The revised checklist includes 22 items selected because empirical evidence indicates that not reporting this information is associated with biased estimates of treatment effect, or because the information is essential to judge the reliability or relevance of the findings. We intended the flow diagram to depict the passage of participants through an RCT. The revised flow diagram depicts information from four stages of a trial (enrollment, intervention allocation, follow-up, and analysis). The diagram explicitly shows the number of participants, for each intervention group, included in the primary data analysis. Inclusion of these numbers allows the reader to judge whether the authors have done an intention-to-treat analysis. In sum, the CONSORT statement is intended to improve the reporting of an RCT, enabling readers to understand a trial's conduct and to assess the validity of its results.

Humans↗
PubMed2001

Biphasic versus monophasic oral contraceptives for contraception.

OBJECTIVES: To compare biphasic oral contraceptives with monophasic oral contraceptives in terms of efficacy, cycle control, and discontinuation due to side effects. Our a priori hypotheses were: (a) biphasic oral contraceptives are less effective in preventing pregnancy than are monophasic oral contraceptives, and (b) biphasic oral contraceptives cause more side effects, give poorer cycle control, and have lower continuation rates. SEARCH STRATEGY: We searched computerized databases MEDLINE, EMBASE, Popline and the Cochrane Controlled Trial Register. Additionally we searched the reference lists of all potentially relevant articles and book chapters. We also contacted the authors of relevant studies and pharmaceutical companies in Europe and the U.S. SELECTION CRITERIA: We included randomized controlled trials comparing any biphasic oral contraceptive with any monophasic oral contraceptive when used to prevent pregnancy. DATA COLLECTION AND ANALYSIS: We examined the studies found during the various literature searches for possible inclusion and assessed their methodological quality using the Cochrane guidelines. We contacted the authors of all included studies and of possibly randomized studies for supplemental information about the study methods and outcomes. We entered the data in RevMan 3.1, imported the data into RevMan 4.1, and calculated Peto odds ratios for the incidence of intermenstrual bleeding, absence of withdrawal bleeding, and study discontinuation due to intermenstrual bleeding. MAIN RESULTS: Only one trial of limited quality compared a biphasic and monophasic preparation. Percival-Smith et al. (1990) examined 533 user cycles of a biphasic pill (norethindrone 500 mcg/ethinyl estradiol 35 mcg for ten days, followed by norethindrone 1000 mcg/ethinyl estradiol 35 mcg for eleven days; Ortho 10/11) and 481 user cycles of a monophasic contraceptive pill (norethindrone acetate 1500 mcg/ethinyl estradiol 30 mcg daily; Loestrin). The study found no significant differences in intermenstrual bleeding, amenorrhea and study discontinuation due to intermenstrual bleeding between the biphasic and monophasic oral contraceptive pills. REVIEWER'S CONCLUSIONS: Conclusions are limited by the identification of only one trial, the methodological shortcomings of that trial, and the absence of data on accidental pregnancies. However, the trial found no important differences in bleeding patterns between the biphasic and monophasic preparations studied. Since no clear rationale exists for biphasic pills and since extensive evidence is available for monophasic pills, the latter are preferred.

Contraception↗
PubMed2001

Biphasic versus triphasic oral contraceptives for contraception.

BACKGROUND: Side effects caused by oral contraceptives discourage compliance with and continuation of oral contraceptives. A suggested disadvantage of biphasic oral contraceptive pills as compared to triphasic oral contraceptive pills is an increase in breakthrough bleeding. We conducted this systematic review to examine this potential disadvantage. OBJECTIVES: To compare biphasic oral contraceptives with triphasic oral contraceptives in terms of efficacy, cycle control, and discontinuation due to side effects. SEARCH STRATEGY: We searched computerized databases MEDLINE, EMBASE, POPLINE and the Cochrane Controlled Trial Register. Additionally we searched the reference lists of potentially relevant articles and book chapters. We also contacted the authors of relevant studies and pharmaceutical companies in Europe and the U.S. SELECTION CRITERIA: We included randomized controlled trial comparing any biphasic oral contraceptive with any triphasic oral contraceptive when used to prevent pregnancy. DATA COLLECTION AND ANALYSIS: We examined the studies found during the various literature searches for possible inclusion and assessed their methodological quality using the Cochrane guidelines. We contacted the authors of all included studies and of possibly randomized studies for supplemental information about the study methods and outcomes. We entered the data in RevMan 3.1 and later imported them into RevMan 4.1. We calculated Peto odds ratios for incidence of incidence of discontinuation due to medical reasons, intermenstrual bleeding, absence of withdrawal bleeding, and discontinuation due to intermenstrual bleeding. MAIN RESULTS: Only two trials of limited quality met our inclusion criteria. Larranaga (1978) compared two biphasic and one triphasic pills, each containing levonorgestrel and ethinyl estradiol. No important differences emerged, and the frequency of discontinuation due to medical problems was similar with all three pills. Percival Smith (1990) compared a biphasic pill containing norethindrone (Ortho 10/11) with a triphasic pill containing levonorgestrel (Triphasil) and another triphasic pill containing norethindrone (Ortho 7/7/7). The biphasic pill had inferior cycle control compared with the levonorgestrel triphasic pill. The odds ratio of cycles with intermenstrual bleeding was 1.7 (95%CI 1.3-2.2) for the biphasic pill compared with the triphasic levonorgestrel pill. The odds ratio of cycles without withdrawal bleeding was 6.5 (95%CI 3.1-13). In contrast, cycle control with the biphasic pill was comparable to that with the triphasic pill containing the same progestin (norethindrone). REVIEWER'S CONCLUSIONS: The available evidence is limited and of poor quality; the internal validity of these trials is questionable. Given the high losses to follow-up after randomization, these reports may be better considered observational in nature. Given that caveat, the biphasic pill containing norethindrone was associated with inferior cycle control compared with the triphasic pill containing levonorgestrel. This suggests that the choice of progestin may be more important that the phasic regimen in determining bleeding patterns.

Contraception↗