864 resultados para Inimizes the chi-square


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Background Synchronization programs have become standard in the dairy industry in many countries. In Switzerland, these programs are not routinely used for groups of cows, but predominantly as a therapy for individual problem cows. The objective of this study was to compare the effect of a CIDR-Select Synch and a 12-d CIDR protocol on the pregnancy rate in healthy, multiparous dairy cows in Swiss dairy farms. Methods Cows (N = 508) were randomly assigned to CIDR-Select Synch (N = 262) or 12-d CIDR (N = 246) protocols. Cows in the CIDR-Select Synch group received a CIDR and 2.5 ml of buserelin i.m. on d 0. On d 7, the CIDR insert was removed and 5 ml of dinoprost was administered i.m.. Cows in the 12-d CIDR group received the CIDR on d 0 and it was removed on d 12 (the routine CIDR protocol in Swiss dairies). On d 0 a milk sample for progesterone analysis was taken. Cows were inseminated upon observed estrus. Pregnancy was determined at or more than 35 days after artificial insemination. As a first step, the two groups were compared as to indication for treatment, breed, stud book, stall, pasture, and farmer's business using chi square tests or Fisher's exact test. Furthermore, groups were compared as to age, DIM, number of AI's, number of cows per farm, and yearly milk yield per cow using nonparametric ANOVA. A multiple logistic model was used to relate the success of the protocols to all of the available factors; in particular treatment (CIDR-Select Synch/12-d CIDR), milk progesterone value, age, DIM, previous treatment of the uterus, previous gynecological treatment, and number of preceding inseminations. Results The pregnancy rate was higher in cows following the CIDR-Select Synch compared to the 12-d CIDR protocol (50.4% vs. 22.4%; P < 0.0001). Conclusion The CIDR-Select Synch protocol may be highly recommended for multiparous dairy cows. The reduced time span of the progesterone insert decreased the number of days open, improved the pregnancy rate compared to the 12-d CIDR protocol and the cows did not to have to be handled more often.

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This study describes the sociolinguistic situation of the indigenous Hungarian national minorities in Slovakia (c. 600,000), Ukraine (c. 180,000), Romania (c. 2,000,000), Yugoslavia (c. 300,000), Slovenia (c. 8,000) and Austria (c. 6,000). Following the guidelines of Hans Goebl et al, the historical sociolinguistic portrait of each minority is presented from 1920 through to the mid-1990s. Each country's report includes sections on geography and demography, history, politics, economy, culture and religion, language policy and planning, and language use (domains of minority and/or majority language use, proficiency, attitudes, etc.). The team's findings were presented in the form of 374 pages of manuscripts, articles and tables, written in Hungarian and English. The core of the team's research results lies in the results of an empirical survey designed to study the social characteristics of Hungarian-minority bilingualism in the six project countries, and the linguistic similarities and differences between the six contact varieties of Hungarian and Hungarian in Hungary. The respondents were divided by age, education, and settlement group - city vs. village and local majority vs. local minority. The first thing to be observed is that Hungarian is tending to be spoken less to children than to parents and grandparents, a familiar pattern of language shift. In contact varieties of Hungarian, analytic constructions may be used where monolingual Hungarians would use a more synthetic form. Mr Kontra gives as an example the compound tagdij, which in Standard Hungarian means "membership fee" but which is replaced in contact Hungarian by the two-word phrase tagsagi dij. Another similar example concerns the synthetic verb hegedult "played the violin" and the analytic expression hegedun jatszott. The contrast is especially striking between the Hungarians in the northern Slavic countries, who use the synthetic form frequently, and those in the southern Slavic countries, who mainly use the analytic form. Mr. Kontra notes that from a structural point of view, there is no immediate explanation for this, since Slovak or Ukrainian are as likely to cause interference as is Serbian. He postulates instead that the difference may be attributable to some sociohistoric cause, and points out that the Turkish occupation of what is today Voivodina caused a discontinuity of the Hungarian presence in the region, with the result that Hungarians were resettled in the area only two and a half centuries ago. However, the Hungarians in today's Slovakia and Ukraine have lived together with Slavic peoples continuously for over a millennium. It may be, he suggests, that 250 years of interethnic coexistence is less than is needed for such a contact-induced change to run its course. Next Mr. Kontra moved on to what he terms "mental maps and morphology". In Hungarian, the names of cities and villages take the surface case (eg. Budapest-en "in Budapest") whereas some names denoting Hungarian settlements and all names of foreign cities take the interior case (eg. Tihany-ban "in Tihany" and Boston-ban "in Boston). The role of the semantic feature "foreign" in suffix-choice can be illustrated by such minimal pairs as Velence-n "in Velence, a village in Hungary" versus Velence-ben "in Velence [=Venice], a city in Italy", and Pecs-en "in Pecs, a city in Hungary" vs. Becs-ben "in Becs, ie. Vienna". This Hungarian vs. foreign distinction is often interpreted as "belonging to historical (pre-1920) Hungary" vs. "outside historical Hungary". The distinction is also expressed in the dichotomy "home" vs. "abroad'. The 1920 border changes have had an impact on both majority and minority Hungarians' mental maps, the maps which govern the choice of surface vs. interior cases with placenames. As there is a growing divergence between the mental maps of majority and minority Hungarians, so there will be a growing divergence in their use of the placename suffixes. Two placenames were chosen to scratch the surface of this complex problem: Craiova (a city in Oltenia, Romania) and Kosovo (Hungarian Koszovo) an autonomous region in southeast Yugoslavia. The assumption to be tested was that both placenames would be used with the inessive (interior) suffixes categorically by Hungarians in Hungary, but that the superessive suffix (showing "home") would be used near-categorically by Hungarians in Romania and Yugoslavia (Voivodina). Minority Hungarians in countries other than Romania and Yugoslavia would show no difference from majority Hungarians in Hungary. In fact, the data show that, contrary to expectation, there is considerable variation within Hungary. And although Koszovo is used, as expected, with the "home" suffix by 61% of the informants in Yugoslavia, the same suffix is used by an even higher percentage of the subjects in Slovenia. Mr. Kontra's team suggests that one factor playing a role in this might be the continuance of the former Yugoslav mentality in the Hungarians of Slovenia, at least from the geographical point of view. The contact varieties of Hungarian show important grammatical differences from Hungarian in Hungary. One of these concerns the variable use of Null subjects (the inclusion or exclusion of the subject of the verb). When informants were asked to insert either megkertem or megkertem ot - "I asked her" - into a test sentence, 54.9% of the respondents in the Ukraine inserted the second phrase as opposed to only 27.4% in Hungary. Although Mr. Kontra and his team concentrated more on the differences between Contact Hungarian and Standard Hungarian, they also discovered a number of similarities. One such similarity is demonstrable in the distribution of what Mr. Kontra calls an ongoing syntactic merger in Hungarian in Hungary. This change means effectively that two possibilities merge to form a third. For instance, the two sentences Valoszinuleg kulfoldre fognak koltozni and Valoszinu, hogy kulfoldre fognak koltozni merge to form the new construction Valszinuleg, hogy kulfoldre fognak koltozni ("Probably they will move abroad."). When asked to choose "the most natural" of the sentences, one in four chose the new construction, and a chi-square test shows homogeneity in the sample. In other words, this syntactic change is spreading across the entire Hungarian-speaking region in the Carpathian Basin Mr. Kontra believes that politicians, educators, and other interested parties now have reliable and up-to-date information about each Hungarian minority. An awareness of Hungarian as a pluricentric language is being developed which elevates the status of contact varieties of Hungarian used by the minorities, an essential process, he believes, if minority languages are to be maintained.

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We introduce a diagnostic test for the mixing distribution in a generalised linear mixed model. The test is based on the difference between the marginal maximum likelihood and conditional maximum likelihood estimates of a subset of the fixed effects in the model. We derive the asymptotic variance of this difference, and propose a test statistic that has a limiting chi-square distribution under the null hypothesis that the mixing distribution is correctly specified. For the important special case of the logistic regression model with random intercepts, we evaluate via simulation the power of the test in finite samples under several alternative distributional forms for the mixing distribution. We illustrate the method by applying it to data from a clinical trial investigating the effects of hormonal contraceptives in women.

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The objective of this study was to examine the potential utility of a commercially available sperm separation and purification product for the in vitro production of bovine embryos. Bovine oocytes were purchased from a commercial supplier, and matured oocytes were randomly allocated to one of two treatments. Oocytes were co-incubated with frozen-thawed semen washed twice with BoviPureTM (BoviPure group) or with modified Brackett-Oliphant medium (control group). After a 6-hour insemination period, oocytes were cultured in vitro for 8 days. Cleavage rate of embryos was determined 48 hours post-insemination, and blastocyst formation rate was assessed on day 8 of culture. The experiment was replicated three times, and data were analyzed using chi-square analysis. Washing of sperm in BoviPureTM had no effect (P>.05) on either cleavage rate (77.2%) or blastocyst development (21.6%) when compared with controls (71.9% and 17.1%, respectively). These results indicate that, under conditions of our study, the washing of sperm with BoviPureTM did not significantly enhance the ability to produce bovine embryos in vitro.

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The distribution of the number of heterozygous loci in two randomly chosen gametes or in a random diploid zygote provides information regarding the nonrandom association of alleles among different genetic loci. Two alternative statistics may be employed for detection of nonrandom association of genes of different loci when observations are made on these distributions: observed variance of the number of heterozygous loci (s2k) and a goodness-of-fit criterion (X2) to contrast the observed distribution with that expected under the hypothesis of random association of genes. It is shown, by simulation, that s2k is statistically more efficient than X2 to detect a given extent of nonrandom association. Asymptotic normality of s2k is justified, and X2 is shown to follow a chi-square (chi 2) distribution with partial loss of degrees of freedom arising because of estimation of parameters from the marginal gene frequency data. Whenever direct evaluations of linkage disequilibrium values are possible, tests based on maximum likelihood estimators of linkage disequilibria require a smaller sample size (number of zygotes or gametes) to detect a given level of nonrandom association in comparison with that required if such tests are conducted on the basis of s2k. Summarization of multilocus genotype (or haplotype) data, into the different number of heterozygous loci classes, thus, amounts to appreciable loss of information.

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This study aims to characterize Azikheli, an undocumented buffalo breed, in its home tract (Khwazakhela, Swat, Pakistan) under traditional farming conditions. For this purpose, 108 buffalo cows and 27 bulls were randomly selected. Mean, standard error, Student's t test and Chi-square test were used for various comparisons. The results show that the majority of animals have a brown coat colour. Cows have significantly higher heart girths, longer horns, longer necks and wider faces at the level of the eyes than bulls, whereas bulls have significantly longer bodies, longer ears, thicker horns, thicker necks and larger hooves than cows. Horns are flat laterally, directed backwards and then slightly upwards without twisting, leading to a sickle to semi-sickle appearance. Owing to its small body size and brown coat colour, the breed is well adapted to mountain slope grazing and thrives well away from swamps. Its adaptation to mountainous ecosystems warrants its in situ conservation.

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Individuals with Lynch syndrome are predisposed to cancer due to an inherited DNA mismatch repair gene mutation. However, there is significant variability observed in disease expression likely due to the influence of other environmental, lifestyle, or genetic factors. Polymorphisms in genes encoding xenobiotic-metabolizing enzymes may modify cancer risk by influencing the metabolism and clearance of potential carcinogens from the body. In this retrospective analysis, we examined key candidate gene polymorphisms in CYP1A1, EPHX1, GSTT1, GSTM1, and GSTP1 as modifiers of age at onset of colorectal cancer among 257 individuals with Lynch syndrome. We found that subjects heterozygous for CYP1A1 I462V (c.1384A>G) developed colorectal cancer 4 years earlier than those with the homozygous wild-type genotype (median ages, 39 and 43 years, respectively; log-rank test P = 0.018). Furthermore, being heterozygous for the CYP1A1 polymorphisms, I462V and Msp1 (g.6235T>C), was associated with an increased risk for developing colorectal cancer [adjusted hazard ratio for AG relative to AA, 1.78; 95% confidence interval, 1.16-2.74; P = 0.008; hazard ratio for TC relative to TT, 1.53; 95% confidence interval, 1.06-2.22; P = 0.02]. Because homozygous variants for both CYP1A1 polymorphisms were rare, risk estimates were imprecise. None of the other gene polymorphisms examined were associated with an earlier onset age for colorectal cancer. Our results suggest that the I462V and Msp1 polymorphisms in CYP1A1 may be an additional susceptibility factor for disease expression in Lynch syndrome because they modify the age of colorectal cancer onset by up to 4 years.

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Our objective was to determine the effect of body mass index (BMI) on response to bacterial vaginosis (BV) treatment. A secondary analysis was conducted of two multicenter trials of therapy for BV and TRICHOMONAS VAGINALIS. Gravida were screened for BV between 8 and 22 weeks and randomized between 16 and 23 weeks to metronidazole or placebo. Of 1497 gravida with asymptomatic BV and preconceptional BMI, 738 were randomized to metronidazole; BMI was divided into categories: < 25, 25 to 29.9, and > or = 30. Rates of BV persistence at follow-up were compared using the Mantel-Haenszel chi square. Multiple logistic regression was used to evaluate the effect of BMI on BV persistence at follow-up, adjusting for potential confounders. No association was identified between BMI and BV rate at follow-up ( P = 0.21). BMI was associated with maternal age, smoking, marital status, and black race. Compared with women with BMI of < 25, adjusted odds ratio (OR) of BV at follow-up were BMI 25 to 29.9: OR, 0.66, 95% CI 0.43 to 1.02; BMI > or = 30: OR, 0.83, 95% CI 0.54 to 1.26. We concluded that the persistence of BV after treatment was not related to BMI.

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Our objective was to determine the effect of body mass index (BMI) on response to bacterial vaginosis (BV) treatment. A secondary analysis was conducted of two multicenter trials of therapy for BV and TRICHOMONAS VAGINALIS. Gravida were screened for BV between 8 and 22 weeks and randomized between 16 and 23 weeks to metronidazole or placebo. Of 1497 gravida with asymptomatic BV and preconceptional BMI, 738 were randomized to metronidazole; BMI was divided into categories: < 25, 25 to 29.9, and > or = 30. Rates of BV persistence at follow-up were compared using the Mantel-Haenszel chi square. Multiple logistic regression was used to evaluate the effect of BMI on BV persistence at follow-up, adjusting for potential confounders. No association was identified between BMI and BV rate at follow-up ( P = 0.21). BMI was associated with maternal age, smoking, marital status, and black race. Compared with women with BMI of < 25, adjusted odds ratio (OR) of BV at follow-up were BMI 25 to 29.9: OR, 0.66, 95% CI 0.43 to 1.02; BMI > or = 30: OR, 0.83, 95% CI 0.54 to 1.26. We concluded that the persistence of BV after treatment was not related to BMI.

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Background: School-based sex education is effective in reducing risky sexual behavior among adolescents that may lead to unintended pregnancies and sexually transmitted infections. However, most sex education policies in the US do not support evidence-based programs. Understanding parental attitudes around sex education is crucial to overcoming perceived barriers to implementing school-based sex education. Little research has been published on the opinions of parents in Texas, which accounts for 12% of the nation’s teen births. Purpose: The purpose of this study was to examine whether Texas parents favor teaching sex education in schools, in what grades they think sex education should be taught, what content they think should be taught, and who they think should make decisions regarding sex education. Methods: We commissioned a telephone survey of parents of children 18 years or younger in Harris County, Texas. Survey questions assessed demographic characteristics and opinions about sex education. We used chi-square tests to examine differences across sociodemographic characteristics. Results: 1,201 parents completed the survey. The majority of parents (80%) responded that sex education should begin in middle school or earlier, and two-thirds said that it should include information about condoms and contraception. Hispanic parents showed the highest support for teaching sex education and providing medically accurate information on condoms and contraception in middle school or earlier. Conclusion: Parents in Harris County overwhelmingly support sex education that includes medically accurate information about condoms and contraception beginning before high school. These data provide evidence to change sex education policies to better reflect parental opinions.

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Introduction: US teens are having sex early; however, the vast majority of schools do not implement evidence-based sexual health education (SHE) programs that could delay sexual behavior and/or reduce risky behavior. This study examines middle school staff’s knowledge, attitudes, barriers, self-efficacy, and perceived support (psychosocial factors known to influence SHE program adoption and implementation). Methods: Professional school staff from 33 southeast Texas middle schools completed an internet or paper-based survey. Prevalence estimates for psychosocial variables were computed for the total sample. Chi-square and t-test analyses examined variation by demographic factors. Results: Almost 70% of participants were female, 37% white, 42% black, 16% Hispanic; 20% administrators, 15% nurses/counselors, 31% non-physical education/non-health teachers, 28% physical education/health teachers; mean age = 42.78 years (SD = 10.9). Over 90% favored middle school SHE, and over 75% reported awareness of available SHE curricula or policies. More than 60% expressed confidence for discussing SHE. Staff perceived varying levels of administrator (28%-56%) support for SHE and varying levels of support for comprehensive sex education from outside stakeholders (e.g., parents, community leaders) (42%-85%). Overall, results were more favorable for physical education/health teachers, nurses/counselors, and administrators (when compared to non-physical education/non-health teachers) and individuals with experience teaching SHE. Few significant differences were observed by other demographic factors. Conclusions: Overall, study results were extremely positive, which may reflect a high level of readiness among school staff for adopting and implementing effective middle school SHE programs. Study results highlight the importance of several key action items for schools.

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A process evaluation of the Houston Childhood Lead Poisoning Prevention Program, 1992-1995, was conducted. The Program's goal is to reduce lead poisoning prevalence. The study proposed to determine to what extent the Program was implemented as planned by measuring how well Program services were actually: (1) received by the intended target population; (2) delivered to children with elevated blood lead levels; (3) delivered in compliance with the Centers for Disease Control and Prevention and Program guidelines and timetables; and (4) able to reduce lead poisoning prevalence among those rescreened. Utilizing a program monitoring design, the Program's pre-collected computer records were reviewed. The study sample consisted of 820 children whose blood lead levels were above 15 micrograms per deciLiter, representing approximately 2.9% of the 28,406 screened over this period. Three blood lead levels from each participant were examined: the initial elevated result; the confirmatory result; and the next rescreen result, after the elevated confirmatory level. Results showed that the Program screened approximately 18% (28,406 of 161,569) of Houston's children under age 6 years for lead poisoning. Based on Chi-square tests of significance, results also showed that lead-poisoned participants were more likely to be younger than 3 years, male and Hispanic, compared to those not lead poisoned. The age, gender and ethnic differences observed were statistically significant (p =.01, p =.00, p =.00). Four of the six Program services: medical evaluations, rescreening, environmental inspections and confirmation, had satisfactory delivery completion rates of 71%-98%. Delivery timetable compliance rates for three of the six services examined: outreach contacts, home visits and environmental inspections were below 32%. However, dangerously elevated blood lead levels fell and lead poisoning prevalence dropped from 3.3% at initial screening to 1.2% among those rescreened, after intervention. From a public health perspective, reductions in lead poisoning prevalence are very meaningful. Based on these findings, the following are recommendations for future research: (1) integrate Program database files by utilizing a computer database management program; (2) target services at Hispanic male children under age 3 years living in the highest risk neighborhoods; (3) increase resources to: improve tracking and documentation of service delivery and provide more non-medical case management and environmental services; and (4) share the evaluation methodology/findings with the Centers for Disease Control and Prevention administrators; the implications may be relevant to other program managers conducting such assessments. ^

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OBJECTIVE To analyze the types of articles and authorship characteristics of three orthodontic journals--American Journal of Orthodontics and Dentofacial Orthopedics (AJODO), The Angle Orthodontist (AO), and European Journal of Orthodontics (EJO)--published between 2008 and 2012 and to assess the differences in content within this period and an earlier period of 1998 to 2002. MATERIALS AND METHODS Each journal's content was accessed through the web edition. From each article, the following parameters were recorded: article type, number of authors, number of affiliations, source of article (referring to the first author's affiliation), and geographic origin. Descriptive statistics were performed and selected parameters were analyzed with the Pearson chi-square or Fisher exact test for independence at the .05 level of significance. RESULTS Review of differences between the two periods showed that the number of publications was almost double. The percentages of multi-authored articles increased. Fewer studies derived from the United States/Canada and European Union countries. Increases for articles from non-European Union countries, Asia, and other countries were found. Characteristics of the second period showed that the EJO and AO published more research articles, whereas the AJODO regularly published case reports and other articles. Approximately 75% of all studies derived from orthodontic departments. CONCLUSIONS The publications from 1998-2002 and 2008-2012 were significantly different both in terms of numbers and characteristics. Within 2008-2012 there were notable differences between the three journals concerning the type and origin of the publications.

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BACKGROUND Methylentetrahydrofolate reductase (MTHFR) plays a major role in folate metabolism and consequently could be an important factor for the efficacy of a treatment with 5-fluorouracil. Our aim was to evaluate the prognostic and predictive value of two well characterized constitutional MTHFR gene polymorphisms for primarily resected and neoadjuvantly treated esophagogastric adenocarcinomas. METHODS 569 patients from two centers were analyzed (gastric cancer: 218, carcinoma of the esophagogastric junction (AEG II, III): 208 and esophagus (AEG I): 143). 369 patients received neoadjuvant chemotherapy followed by surgery, 200 patients were resected without preoperative treatment. The MTHFR C677T and A1298C polymorphisms were determined in DNA from peripheral blood lymphozytes. Associations with prognosis, response and clinicopathological factors were analyzed retrospectively within a prospective database (chi-square, log-rank, cox regression). RESULTS Only the MTHFR A1298C polymorphisms had prognostic relevance in neoadjuvantly treated patients but it was not a predictor for response to neoadjuvant chemotherapy. The AC genotype of the MTHFR A1298C polymorphisms was significantly associated with worse outcome (p = 0.02, HR 1.47 (1.06-2.04). If neoadjuvantly treated patients were analyzed based on their tumor localization, the AC genotype of the MTHFR A1298C polymorphisms was a significant negative prognostic factor in patients with gastric cancer according to UICC 6th edition (gastric cancer including AEG type II, III: HR 2.0, 95% CI 1.3-2.0, p = 0.001) and 7th edition (gastric cancer without AEG II, III: HR 2.8, 95% CI 1.5-5.7, p = 0.003), not for AEG I. For both definitions of gastric cancer the AC genotype was confirmed as an independent negative prognostic factor in cox regression analysis. In primarily resected patients neither the MTHFR A1298C nor the MTHFR C677T polymorphisms had prognostic impact. CONCLUSIONS The MTHFR A1298C polymorphisms was an independent prognostic factor in patients with neoadjuvantly treated gastric adenocarcinomas (according to both UICC 6th or 7th definitions for gastric cancer) but not in AEG I nor in primarily resected patients, which confirms the impact of this enzyme on chemotherapy associated outcome.

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Objective. The objective of this study was to determine the prevalence of unintended pregnancy and the association between social and demographic factors among a population of active duty women in the U.S. Army giving birth to viable infants at a U.S. Army hospital at Fort Hood, Texas. Prevalence of unintended pregnancy in this group was 50.9% (95% CI 44.0 to 57.9) with 36.3% being mistimed (95% CI 29.8 to 33.2) and 14.6% being unwanted (95% CI 10.2 to 20.1). A further 14.2% of the women experienced ambivalence (95% CI 9.8 to 19.6). ^ The study population was a cross-sectional group of active duty pregnant women who represent the target population of all female soldiers that deliver viable infants in the Army. Using a survey based on previous studies, intendedness of pregnancy at conception was retrospectively determined. Unintended births are further characterized as mistimed or unwanted. Demographic and other exposures were described bivariately. Associations were evaluated using measures of relative risk and chi-square analysis. ^ The results of the research indicate that in the study population, race/ethnicity is not associated with unintended pregnancy and non-commissioned officers had a lower rate of unintended pregnancy than other rank groupings. ^