Biomedical subjects

Ken R Smith

Publications and source records attributed to Ken R Smith.

12 recordsLinked to original sources

PubMed2007

Familial effects of BRCA1 genetic mutation testing: changes in perceived family functioning.

This study expands recent research that examines how the receipt of BRCA1 genetic test results affects family adaptability and cohesion 1 year after genetic risk notification. Study participants were members of a large Utah-based kindred with an identified mutation at the BRCA1 locus. The final sample, 90 men and 132 women, contributed information before genetic testing (baseline) and 4 months and/or 1 year after receipt of genetic test results. After controlling for other factors such as family coping resources (Family Crises-Oriented Personal Evaluation Scale) and strains (Family Strains Index) and the tested individual's anxiety levels before genetic testing (state anxiety subscale), men and women reported significant declines in family cohesion 1 year after genetic risk notification (P < 0.01). There is suggestive evidence that carrier men reported increasing adaptability 1 year after risk notification (+0.21 points per month; P < 0.10). Having a carrier sister had a positive influence on women's perceived family cohesion and adaptability levels, whereas a personal history of cancer, having a great deal of caregiving involvement for a female relative with cancer, anxiety, and some types of coping resources had a negative effect on men's perceived family cohesion and adaptability levels. Although results showed that tested parents are perceiving a decline in family functioning after genetic risk notification, there is no evidence to suggest that the decline is due to carrier status. In fact, it is other life circumstances that exist at the time of the genetic testing process that seem to influence the degree to which families adjust to the experience and test results.

Adaptation, Psychological↗

PubMed2006

Differential fitness costs of reproduction between the sexes.

Natural selection does not necessarily favor maximal reproduction because reproduction imposes fitness costs, reducing parental survival, and offspring quality. Here, we show that parents in a preindustrial population in North America incurred fitness costs from reproduction, and women incurred greater costs than men. We examined the survivorship and reproductive success (Darwinian fitness) of 21,684 couples married between 1860 and 1895 identified in the Utah Population Database. We found that increasing number of offspring (parity) and rates of reproduction were associated with reduced parental survivorship, and significantly more for mothers than fathers. Parental mortality resulted in reduced survival and reproduction of offspring, and the mothers' mortality was more detrimental to offspring than the fathers'. Increasing family size was associated with lower offspring survival, primarily for later-born children, indicating a tradeoff between offspring quantity versus quality. Also, we found that the costs of reproduction increased with age more for women than men. Our findings help to explain some puzzling aspects of human reproductive physiology and behavior, including the evolution of menopause and fertility declines associated with improvements in women's status (demographic transitions).

Adolescent↗

PubMed2005

Communication analysis of BRCA1 genetic counseling.

In this study, we apply an existing medical communication coding system to BRCA1 genetic counseling sessions, describe the session dynamics, and explore variation in session communication. The sample was comprised of 167 members of an identified BRCA1 kindred whose pretest counseling session was audiotaped and coded using Roter's Interaction Analysis System (RIAS). Three certified genetic counselors followed a research protocol that dictated areas to be covered in the counseling session. We found that it was feasible to code long, protocol driven BRCA1 sessions in a quantitative manner without the use of transcripts and capture the dialogue of all session participants. These findings support the use of RIAS in genetic counseling research. Our results indicate that these BRCA1 sessions were predominantly educational in nature with minimal dialogue devoted to psychosocial issues. We found that participant gender, presence of a client companion, and counselor identity influence session communication.

Communication↗

PubMed2004

Fertility intentions following testing for a BRCA1 gene mutation.

OBJECTIVE: To test whether fertility intentions differed among persons who tested positive, tested negative, or did not know their genetic status for a mutation of the BRCA1 gene. METHOD: Participants were members of a large Utah-based kindred with an identified mutation at the BRCA1 locus. Participants received genetic counseling prior to testing and were interviewed at baseline before testing and at three points after receiving test results from a genetic counselor. The sample included men and women who completed all interviews, were between ages 18 and 45, and were fertile, resulting in a sample of 101 respondents. The primary dependent variable measured whether a subject indicated that they were moderately or very sure at all three post-testing interviews that they intended to have additional children. Effects of BRCA1 mutation status on fertility intentions were estimated using multivariate logistic regressions where we controlled for gender, age, marital status, and baseline fertility intentions. RESULTS: Female carriers were less likely to want additional children in relation to female noncarriers (odds ratio 0.12, 95% confidence interval 0.01-1.23; P = 0.074). No differences were found among men. There was a significant difference in the effect of mutation status on fertility intentions between males and females (Gender x Carrier status interaction; P = 0.009). Persons who did not know their mutation status were less likely to want more children than noncarriers (odds ratio 0.09, 95% confidence interval 0.01-0.75; P = 0.027). CONCLUSION: Predictive genetic testing for late-onset cancer susceptibility affects family planning decision-making. Persons contemplating predictive testing should be informed about possible effects such testing may have on their plans for future fertility.

Adolescent↗

PubMed2003

Effects of spouses on distress experienced by BRCA1 mutation carriers over time.

Concerns about psychological distress have arisen regarding genetic testing for susceptibility to late-onset diseases such as breast and/or ovarian cancer. Early results do not show large-scale psychological distress among those tested; therefore, research is now focusing on identifying subgroups that may be at risk for negative outcomes. Social support has been shown to buffer both negative physical and psychological outcomes in health research. The role of spouses as part of the tested person's social support system is shown to be significant in a sample of 57 BRCA1 mutation carriers. Separately, the tested person's perception of his/her spouse's anxiety and his/her perception of the spouse's support at the time of testing are predictive of the tested person's psychological distress up to 2 years after testing. The interaction of the two variables is even more predictive. For those tested who perceived their spouse to be both anxious and nonsupportive at the time of testing, distress levels reached clinically significant levels 1 week after results were received and remained above clinical threshold measured 4 months, 1 year, and 2 years after testing. While the effects were greatest for women, they were significant for both male and female carriers. These findings are an important addition to the literature and will augment clinicians' ability to identify individuals potentially at risk for negative responses to adverse genetic test results.

Concept Formation↗

PubMed2003

Genetic testing for a BRCA1 mutation: prophylactic surgery and screening behavior in women 2 years post testing.

Mutations in the BRCA1 gene are associated with an increased risk of breast and ovarian cancer in carrier women. An understanding of behavioral responses to BRCA1 mutation testing by mutation carriers and non-carriers is important to guide the clinical application of this new technology. This study examined the utilization of genetic testing for a BRCA1 mutation in high-risk individuals and the response of tested women with respect to interventions for early cancer detection and prevention. This study assessed the utilization of genetic testing for both men and women in a large kindred and the behavioral responses by women with respect to use of health care interventions during the 2 years following testing. Participants were offered BRCA1 mutation testing. Surveillance behaviors related to breast and ovarian cancer were assessed by computer-assisted telephone interviews at baseline (prior to genetic counseling and testing), 1-2 weeks, 4-6 months, 1 and 2 years after the provision of test results. Mutation carriers, non-carriers, and individuals of unknown mutation status were compared to determine the impact of test results. Utilization of genetic testing for both men and women are reported and, for women, mammography, breast self-exam, clinical breast exam, mastectomy, oophorectomy, transvaginal ultrasound, and CA125 screening were assessed. Of those fully informed of the opportunity for testing, 55% of the women and 52% of the men pursued genetic testing. With respect to mammography for women 40 years and older, 82% of mutation carriers obtained a mammogram in each year following testing compared to 72% of non-carrier women the first year and 67% the second year. This mammography utilization represents a significant increase over baseline for both mutation carriers and non-carriers. Younger carrier women also significantly increased their mammography utilization from baseline. Overall, 29% of the carrier women did not obtain a single mammogram by 2 years post-testing. At 2 years, 83% of the carrier women and 74% of the non-carriers reported adherence to recommendations for breast self-exam and over 80% of carrier women had obtained a clinical breast examination each year following testing. None of the carrier women had obtained a prophylactic mastectomy by 2 years after testing, although 11% were considering this procedure. Of carrier women 25 years of age and older who had at least one intact ovary at the time of testing, 46% of carriers had obtained an oophorectomy 2 years after testing, including 78% of women 40 years of age and older. The majority of carrier women (73%) had discussed their genetic test results with a medical doctor or health care provider. Our results indicate utilization of genetic testing by a majority of high-risk individuals who received information about testing. Both carriers and non-carriers increased their utilization of mammography and breast self-exam following testing. Oophorectomy was obtained by a large proportion of carrier women in contrast to mastectomy which was not utilized within the first 2 years following testing.

Adult↗

PubMed2003

Association between telomere length in blood and mortality in people aged 60 years or older.

During normal ageing, the gradual loss of telomeric DNA in dividing somatic cells can contribute to replicative senescence, apoptosis, or neoplastic transformation. In the genetic disorder dyskeratosis congenita, telomere shortening is accelerated, and patients have premature onset of many age-related diseases and early death. We aimed to assess an association between telomere length and mortality in 143 normal unrelated individuals over the age of 60 years. Those with shorter telomeres in blood DNA had poorer survival, attributable in part to a 3.18-fold higher mortality rate from heart disease (95% CI 1(.)36-7.45, p=0.0079), and an 8.54-fold higher mortality rate from infectious disease (1.52-47.9, p=0.015). These results lend support to the hypothesis that telomere shortening in human beings contributes to mortality in many age-related diseases.

Age Distribution↗

PubMed2003

Vulvar mucus observations and the probability of pregnancy.

OBJECTIVE: To assess the day-specific and cycle-specific probabilities of conception leading to clinical pregnancy, in relation to the timing of intercourse and vulvar mucus observations. METHODS: This was a retrospective cohort study of women beginning use of the Creighton Model Fertility Care System in Missouri, Nebraska, Kansas, and California. Data were abstracted from Creighton Model Fertility Care System records, including women's daily standardized vulvar observations of cervical mucus discharge, days of intercourse, and clinically evident pregnancy (conception). Established statistical models were used to estimate day-specific probabilities of conception. RESULTS: Data were analyzed from 1681 cycles with 81 conceptions from 309 normally fertile couples (initially seeking to avoid pregnancy) and from 373 cycles with 30 conceptions from 117 subfertile couples (who were initially trying to achieve pregnancy). The highest probability of pregnancy occurred on the peak day of vulvar mucus observation (.38 for normally fertile couples and.14 for subfertile couples). The probability of pregnancy was greater than.05 for normally fertile couples from 3 days before to 2 days after the peak, and for subfertile couples from 1 day before to 1 day after the peak. The cycle-specific probability of conception correlated with the quality of mucus discharge in normally fertile couples but not in subfertile couples. CONCLUSION: Standardized vulvar observations of vaginal mucus discharge identify the days with the greatest likelihood of conception from intercourse in normal fertility and subfertility and provide an indicator of the overall potential for conception in a given menstrual cycle in normal fertility.

Cervix Mucus↗

PubMed2002

Historical trends of survival among widows and widowers.

One of the most consistent findings in social demography is that recently widowed individuals, male or female, have higher rates of mortality than comparable married persons. These results are based generally on contemporary studies in developed nations where life expectancy is high. Because of data limitations, there are few studies available to determine whether these findings also occur when mortality rates were higher. This study uses the Utah Population Database that was developed from extensive family genealogies and now linked to Utah death certificates. These data make it possible to employ life course analysis of four marriage cohorts extending from 1860 through 1904 with mortality follow-up to 1990. This approach is used to compare mortality risks of widowed males and females relative to comparable married individuals. Covariates included in the study are remarriage, as well as religion and number of children ever born; these are all hypothesized to have protective effects on mortality risks for widowed men and women. Analysis of these data indicates that there are significant differences in the mortality risk for widowed men and women, and it is widowed men who have an excess risk of dying in every cohort and nearly every age. A consistent pattern of excess mortality in the comparison of married and widowed women was not observed. There are significant female and male differences in the effect of religion which was treated as a proxy for life style and social support: however, remarriage as a proxy for social support has similar protective effects on the surviving spouse.

Adult↗

PubMed2002

Voluntary disclosure of BRCA1 mutation test results.

This study assessed the probability that individuals tested for a BRCA1 gene mutation share their test results with family members, co-workers, and insurers. Members of a large kindred known to be at-risk for carrying a BRCA1 gene mutation were tested and they learned their results from a genetic counselor. During a follow-up interview, 4 months later, subjects were asked with whom they had shared their results. Respondents were most likely to have communicated results to family members, followed by co-workers, and insurers. Carrier status affected their willingness to disclose results to insurers. High rates of disclosure to family members should promote awareness of hereditary cancer risk. Selective disclosure to co-workers and insurers may promote information asymmetries that could affect employment and insurance markets.

Adult↗

PubMedDate not supplied

Fertility and post-reproductive longevity.

We examine the effects of reproduction on longevity among mothers and fathers after age 60. This study is motivated by evolutionary theories of aging and theories predicting social benefits and costs of children to older parents. We use the Utah Population Database, that includes a large genealogical database from the Utah Family History Library. Cox proportional hazard models based on 13,987 couples married between 1860-1899 indicate that women with fewer children as well as those bearing children late in life live longer post-reproductive lives. As the burdens of motherhood increase, the relative gains in longevity of late fertile women increase compared to their non-late fertile counterparts. Husbands' longevity is less sensitive to reproductive history, although husbands have effects that are similar to those of their wives during the latter marriage cohort. We find some support for predictions based on evolutionary principles, but we also find evidence that implicates a role for shared marital environments.

Age Factors↗

PubMedDate not supplied

Double impact: what sibling data can tell us about the long-term negative effects of parental divorce.

Most prior research on the adverse consequences of parental divorce has analyzed only one child per family. As a result, it is not known whether the same divorce affects siblings differently. We address this issue by analyzing paired sibling data from the 1994 General Social Survey (GSS) and 1994 Survey of American Families (SAF). Both seemingly unrelated regressions and random effects models are used to study the effect of family background on offspring's educational attainment and marital stability. Parental divorce adversely affects the educational attainment and the probability of divorce of both children within a sibship; in other words, siblings tend to experience the same divorce the same way. However, family structure of origin only accounts for a trivial portion of the shared variance in offspring's educational attainment and marital stability, so parental divorce is only one of many factors determining how offspring fare. These findings were unchanged when controlling for a number of differences both between and within sibships. Also, the negative effects of parental divorce largely do not vary according to respondent characteristics.

Adolescent↗