A scale to measure microbehaviors of oral contraceptive pill use

The ways in which contraceptive methods are actually used is of increasing interest to researchers, clinicians, and policy makers. Although contraceptive "use" has multiple dimensions, existing indicators measure only one aspect of use or combine unidimensional measures to produce a questionable pastiche. This study uses a subsample of 612 respondents from a larger study of first-time patients at a public-health-department family planning clinic to develop a new measure. Psychometric properties of this measure are examined and discussed.     

A scale to measure microbehaviors of oral contraceptive pill use

Abstract

The ways in which contraceptive methods are actually used is of increasing interest to researchers, clinicians, and policy makers. Although contraceptive “use” has multiple dimensions, existing indicators measure only one aspect of use or combine unidimensional measures to produce a questionable pastiche. This study uses a subsample of 612 respondents from a larger study of first‐time patients at a public‐health‐department family planning clinic to develop a new measure. Psychometric properties of this measure are examined and discussed.     

Determinants of contraceptive use in Nepal

This 1981 study is the 1st of its kind in Nepal. Analysis using a logit-linear model showed that contraceptive use in Nepal depends on many factors. Women aged 35-49 are 3 times more likely than women aged 15-24 to use contraceptives. Women with 4 or more children are 8 times more likely to use contraceptives than women with 1 or no children, and 2.5 times more likely than women with 2 or 3 children. The use of contraceptives is greatest among women whose offspring includes more sons than daughters, and least among women whose offspring are all daughters. Women who desire no more children are 5 to 6 times more likely to use contraceptives than women who desire more children. Women who have discussed desired family size with their husbands are more than 4 times more likely to use contraceptives than women lacking this type of communication. Women with some schooling are twice as likely to use contraceptives as women with no schooling. Contraceptive use is higher among women who do nonfarm work than farm work, and higher still among women who do not work. Urban women were almost twice as likely to use contraceptives as rural women. Women with less than 1 hour access to a family planning service outlet were 2 to 3 times more likely to use contraceptives than women whose access to these facilities was greater than 1 hour. The number of previous child losses per woman had no significant effect in contraceptive use. Conclusions are based on analysis of data from the Nepal Contraceptive Prevalence Survey, 1981.     

A new procedure to derive weighting factors for nonlinear regression analysis applied to enzyme kinetic data.

The experimental variance of enzymic steady-state kinetic experiments depends on velocity as approximated by a power function (Var(v) = K1 . valpha (Askel?f, P., Korsfeldt, M. and Mannervik, B. (1976) Eur. J. Biochem. 69, 61--67). The values of the constants (K1, alpha) can be estimated by making replicate measurements of velocity, and the inverse of the function can then be used as a weighting factor. In order to avoid measurement of a large number of replicates to establish the error structure of a kinetic data set, a different approach was tested. After a preliminary regression using a 'good model', which satisfies reasonable goodness-of-fit criteria, the residuals were taken to represent the experimental error. The neighbouring residuals were grouped together and the sum of their mean squared values was used as a measure of the variance in the neighbourhood of the corresponding measurements. The values of the constants obtained in this way agreed with those obtained by replicates.     

When to use what: Methods for weighting and aggregating sustainability indicators

ContextSustainability indices (SIs) have become increasingly important to sustainability research and practice. However, while the validity of SIs is heavily dependent on how their components are weighted and aggregated, the typology and applicability of the existing weighting and aggregation methods remain poorly understood.ObjectivesTo close the knowledge gap regarding when to use which weighting and aggregation methods for constructing SIs, we review the most commonly used methods for weighting and aggregating SIs, discuss their benefits and drawbacks, and suggest a process-oriented approach for choosing appropriate weighting and aggregation methods depending on research objectives.MethodsOur review synthesis was based on peer-reviewed journal articles, books, and reports by international organizations, governmental agencies, and research institutions. After carefully examining their principles, characteristics, and applications, we selected and classified the frequently used methods for indicator weighting and aggregation.ResultsWe systematically discuss the benefits and drawbacks of nine weighting methods and three aggregation methods. We propose a four-step process for choosing the most suitable weighting and aggregation methods based on: research purposes, spatial and temporal scales, and sustainability perspectives.ConclusionsIn this research, we chose the most commonly used methods for weighting and aggregating SIs and analyzed the characteristics, strengths and weaknesses of each method. We found that choosing appropriate weighting and aggregation methods for a specific sustainability assessment project is an extremely important and challenging task. To meet this challenge, we propose a process-oriented approach for properly selecting methods according to the purpose, scale and sustainability concept. This approach can facilitate the proper selection of these methods in sustainability research and practice.     

Changes in contraceptive use and fertility: Panama, 1976 to 1984

Abstract

From 1976 to 1984 important demographic changes occurred in Panama. The total fertility rate declined from 4.5 to 3.7, and contraceptive use amongmarried women 20–44 years of age increased from 55 per cent to 63 per cent. However, using data from three national level reproductive health surveys which were conducted in Panama in 1976, 1979, and 1984, we found that most of the changes took place between 1976 and 1979. Since 1979, overall contraceptive use and fertility have remained virtually unchanged, although there has been an important method‐mix shift toward an increase in the use of contraceptive sterilization and IUD's, with an accompanying decline in the use of oral contraceptives. Although the singulate mean age at marriage remained relatively constant, the average duration of breastfeeding rose 23 per cent during the period. Further gains in contraceptive prevalence and reduction in unplanned fertility in Panama will largely depend on enhanced program efforts first begun in the early 1970's by the Panama Ministry of Health. Future program efforts especially should be directed toward encouraging young couples to space their children more effectively by using temporary methods of contraception.     

Determinants of contraceptive use and method choice in Turkey

In this study, the determinants of contraceptive use and method choice are examined based on various variables, classified as individual, cultural, fertility and contextual. The data used came from the 1993 Turkish Demographic and Health Survey. The main finding is that there exists a positive association between the educational level of both spouses and the use of contraceptive methods in Turkey. After all individual, cultural, fertility and contextual variables are controlled, a woman's education is a stronger predictor of method use and method choice than that of her husband. Increasing the educational level of women may be the most effective means of advancing family planning acceptance and increasing the demand for contraceptive services in Turkey. The study also shows that, to a great extent, contraceptive use and choice of modern method depend on the sex of a couple's living children, implying some preference for sons, although generally women prefer to have children of both sexes.     

Ethnicity and contraceptive use in sub-Saharan Africa: the case of Ghana

Using a sub-sample of ever-married women from the 1993 Ghana Demographic and Health Survey (GDHS), this study examines differentials in contraceptive use in six cultural groups: Ga-Adangbe, Twi, Fante/other Akans, Ewe, Guan/others and Mole-Dagbani. Multivariate analysis is used to explore whether reported ethnic differentials in contraceptive use can be attributed to ethnicity or to other characteristics that distinguish the ethnic groups. Overall, the findings are generally more consistent with the 'characteristics' hypothesis, because contraceptive use differentials by ethnic group is accounted for by differences in socioeconomic and demographic characteristics of these women. However, for the Fante/other Akans, even after the necessary controls, ethnicity continued to emerge as a significant determinant of contraceptive use. Programmatic implications of these results are discussed.     

Zero-length crosslinking procedure with the use of active esters

A two-step zero-length crosslinking procedure for studying protein-protein complexes has been developed. One component of a complex is briefly incubated with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) in the presence of N-hydroxysuccinimide resulting in the conversion of some of the protein carboxyls into succinimidyl esters. The reaction is stopped by addition of beta-mercaptoethanol and other interacting proteins are then added. Crosslinking arises from substitution of lysine epsilon-amino groups of these proteins for the succinimidyl moieties during a 1- to 2-h incubation period. The advantage of this method versus one-step zero-length crosslinking is that only one component of the complex is exposed to the crosslinker, which eliminates complications arising from the formation of crosslinks among several proteins of a multicomponent complex. Furthermore, crosslinks can be formed even in the presence of reagents, such as dithiothreitol and EDTA, that would interfere with direct crosslinking with EDC.     

Duration of oral contraceptive use predicts women's initial and subsequent subjective responses to sexual stimuli

Recent work suggests that a woman's hormonal state when first exposed to visual sexual stimuli (VSS) modulates her initial and subsequent responses to VSS. The present study investigated whether women's initial hormonal state was related to their subjective ratings of VSS, and whether this relationship differed with VSS content. We reanalyzed previously collected data from 14 naturally cycling (NC) women and 14 women taking oral contraceptives (OCs), who subjectively rated VSS at three hormonal time-points. NC women's ratings of 216 unique sexual images were collected during the menstrual, periovulatory, and luteal phases of their menstrual cycles, and OC women's ratings were collected at comparable time-points across their pill-cycles. NC women's initial hormonal state was not related to their ratings of VSS. OC women's initial hormonal state predicted their ratings of VSS with minimal contextual information and of images depicting female-to-male oral sex. Specifically, women who entered the study in the third week of their pill-cycle (OC-3 women) rated such images as less attractive at all testing sessions than did all other women. OC-3 women were also the only women to rate decontextualized VSS as unattractive at all testing sessions. These results corroborate previous studies in which women's initial hormonal state was found to predict subsequent interest in sexual stimuli. Future work, with larger samples, should more directly investigate whether OC-3 women's negative assessment of specific types of VSS reflects a reaction to the laboratory environment or a broader mechanism, wherein OC women's sexual interests decrease late in their pill-cycle.     

Oral contraceptive use and increased plasma concentration of C-reactive protein

We examined, in young adult women, the association between current low dose oral contraceptive (OC) use and plasma levels of C-reactive protein (CRP), an acute phase reactant predictive of cardiovascular disease risk. We conducted a cross-sectional analysis of 30 healthy, non-smoking, non-obese women (18 OC users and 12 nonusers) who were subjects in a randomized diet-controlled trial of the effects of soy intake on sex hormone metabolism. The study was sited at a university outpatient general clinical research center. Fasting plasma CRP levels were measured 4 times during 2 menstrual cycles (2 mid-follicular phase and 2 mid-luteal phase) using a high-sensitivity CRP assay. Differences between OC users and nonusers were examined by 3-way analysis of variance. Multiple regression was used to examine the relationship between OC use and CRP. There were no significant differences in baseline demographic characteristics between OC users and nonusers. Plasma CRP levels (mean +/- SE) were 2 times higher among OC users than among non-users (2.0 +/- 0.2 versus 0.9 +/- 0.3 mg/l, p<0.0001) independent of diet assignment, diet treatment order, and phase of the menstrual cycle. In a multivariate model, OC use predicted 32 percent of the variance in CRP levels (p<0.0001). As all CRP levels were within a previously established normal range, further study is indicated to establish the clinical significance of the observed elevated CRP levels in OC users.     

Effect of child survival on contraceptive use in Bangladesh.

A study in Bangladesh showed that couples who lost a child often stopped practising contraception in order to have another child. Logistic regression analysis revealed that contraceptive continuation was related to maternal age, parity, husband's education and the sex of the last child.     

The implications of changing hormonal contraceptive use after relationship formation

Modern-day environments differ drastically from those in which humans evolved, which likely has important implications for human mating psychology. Particularly notable is the modern advancement of hormonal contraceptives (HCs), which alter the natural hormones of the many women who use them. According to the HC congruency hypothesis, HCs alter sex hormones and brain processes that are linked to numerous relationship preferences. In light of work suggesting such preferences play an important role in relationship evaluations, changing HC use during a long-term relationship (relative to use at relationship formation) should impact women's relationships. We used data from two independent longitudinal studies of 203 newlywed couples to address this possibility. Results demonstrated that wives reported lower sexual satisfaction (but not marital satisfaction) when their HC use was incongruent (versus congruent) with their use at relationship formation. These findings provide preliminary support for the HC congruency hypothesis, though we also broaden our theoretical framework to offer methodological recommendations for future research.     

Determinants of current contraceptive use and method choice in Mongolia

This study examines the determinants of current contraceptive use and method choice in Mongolia using data from the 1998 Mongolian Reproductive Health Survey and 2000 Mongolian Population and Housing Census. Since 1976, access to modern contraceptives has been liberalized and all restrictions on the use, distribution and import of contraceptives were removed in 1989. There were some increases in the use of modern contraceptives among married women in the 1990s; however, at the start of the twenty-first century the IUD and periodic abstinence remain the most widely used methods. Women with higher levels of education are more likely to be current users of contraception, and if they are current users, they are more likely to choose the IUD and traditional methods. Women living in rural areas have a higher probability of using contraception and are more likely to choose the IUD and traditional methods. Significant variations exist between primary sampling units in current contraceptive use and in the choice of modern methods. Community-level variables were important predictors in reducing variation between primary sampling unit, when other modern methods were compared with traditional methods.