Michael Szafron

Inequities in cervical cancer screening among Colombian women: A multilevel analysis of a nationwide survey

OBJECTIVES To identify factors associated with whether women in Colombia have had a Pap test, evaluate differences in risk factors between rural and urban residence, and evaluate the contextual effect of the lack of education on having ever had a Pap test. METHOD Data used were from the 2010 Colombian National Demographic and Health Survey; 40,392 women reported whether they have had a Pap test. A multilevel mixed logistic regression model was developed with random intercepts to account for clustering by neighbourhood and municipality. The model evaluated whether having a rural/urban area of residence modified the effect of identified risk factors and if the prevalence of no education at the neighbourhood level acted as a contextual effect. RESULTS Most women (87.3%) reported having at least one Pap test. Women from lower socioeconomic quintiles (p=0.002), who were unemployed (p<0.001), and whose final health decisions depended on others (p<0.001) were less likely to have had a Pap test. Women with children were more likely to have had the test (p<0.001), and the effects of education (p=0.03), type of health insurance (p=0.01), age (p<0.001), and region (p<0.001) varied with having a rural/urban area of residence. Women living in rural areas (specifically younger ones, with no health insurance, living in the Atlantic and Amazon-Orinoquía regions, and with no education) were less likely to have had a Pap test when compared to those living in urban areas. Furthermore, women living in a neighbourhood with a higher prevalence of no education were less likely to have ever had a Pap test (p=0.005). CONCLUSIONS In Colombia, the probability of having had a Pap test is associated with personal attributes, area of residence, and prevalence of no education in the neighbourhood. Efforts to improve access to cervical cancer screening should focus on disadvantaged women with limited education, low socioeconomic status, and no health insurance or subsidised insurance, especially those in rural/isolated areas.

Effects of low-dose ibuprofen supplementation and resistance training on bone and muscle in postmenopausal women: A randomized controlled trial

Purpose To compare the effects of nine months of exercise training and ibuprofen supplementation (given immeditately after exercise sessions) on bone and muscle in postmenopausal women. Methods In a double-blind randomized trial, participants (females: n = 90, mean age 64.8, SD 4.3 years) were assigned (computer generated, double blind) to receive supervised resistance training or stretching 3 days/week, and ibuprofen (400 mg, post-exercise) or placebo (i.e. 4 groups) for 9 months. In this proof-of-concept study the sample size was halved from required 200 identified via 90% power calculation. Baseline and post-intervention testing included: Dual energy x-ray absorptiometry (DXA) for lumbar spine, femoral neck, and total body areal bone mineral density (aBMD); geometry of proximal femur; total body lean tissue and fat mass; predicted 1-repetition maximum muscle strength testing (1RM; biceps curl, hack squat). Results Exercise training or ibuprofen supplementation had no effects on aBMD of the lumbar spine, femoral neck, and total body. There was a significant exercise × supplement × time interaction for aBMD of Wards region of the femoral neck (p = 0.015) with post hoc comparison showing a 6% decrease for stretching with placebo vs. a 3% increase for stretching with ibuprofen (p = 0.017). Resistance training increased biceps curl and hack squat strength vs. stretching (22% vs. 4% and 114% vs. 12%, respectively) (p < 0.01) and decreased percent body fat compared to stretching (2% vs. 0%) (p < 0.05). Conclusions Ibuprofen supplementation provided some benefits to bone when taken independent of exercise training in postmenopausal women. This study provides evidence towards a novel, easily accessible stimulus for enhancing bone health [i.e. ibuprofen].

Signed Unknotting Number and Knot Chirality Discrimination via Strand Passage

Which chiral knots can be unknotted in a single step by a + to − (+−) crossing change, and which by a − to + (−+) crossing change? Numerical results suggest that if a knot with 6 or fewer crossings can be unknotted by a +− crossing change then it cannot be unknotted by a −+ one, and vice versa. However, we exhibit one chiral 8-crossing knot and one chiral 9-crossing knot which can be unknotted by either crossing change. Furthermore, we address the question analytically using results of Taniyama and Traczyk. We apply Taniyama’s classification of unknotting operations to chiral rational knots and fully classify all those which, in a single step, can be unknotted by either type of crossing change; the first of these is 813. As a corollary, we obtain Stoimenow’s result that all chiral twist knots can be unknotted by only one of the two crossing change types, +− or −+. Thus, as was observed numerically, all chiral knots with unknotting number one, and seven or fewer crossings, can be unknotted by only one of the two crossing change types. Traczyk’s results allow us to address the question for some non-rational chiral unknotting number one knots with 9 or fewer crossings, however, for others the question remains open. We propose a numerical approach for investigating the latter type of knot. We also discuss the implications of our work in the context of DNA topology.

New evidence on the asymptotics of knotted lattice polygons via local strand-passage models

Two simple-cubic-lattice models of local strand passage in self-avoiding polygons are used to study the asymptotic properties of knot probabilities. Using Monte Carlo simulations of fixed knot-type, variable-length polygons for knot-types , we investigate the limiting (as polygon length goes to ∞) knot-transition probability to go from knot-type K to knot-type K′ after a single strand passage. For knot-types K and Kb, we present numerical evidence that the model-dependent limiting knot-transition probability to go from knot-type K to K′ = K#Kb is independent of the original knot-type K, and that the limiting knot-transition probability is zero for any transition from K to a knot K′ which does not have K in its prime-knot decomposition. These results provide new numerical evidence in support of the conjectured asymptotic form, , for the number of n-edge polygons with fixed knot-type K, where α0 and μ0 are respectively the entropic critical exponent and limiting entropy per edge for unknotted lattice polygons and fK is the number of prime knots in K’s prime-knot decomposition.

The effect of juxtaposition angle on knot reduction in a lattice polygon model of strand passage

A model of local strand passage in self-avoiding polygons (SAPs) on the simple cubic lattice is investigated numerically. The polygons studied, called Θ-SAPs, contain a specific strand-passage structure, called Θ, at a fixed strand-passage site. After-strand-passage knot probabilities are estimated from a Monte Carlo study of unknotted and trefoil Θ-SAPs and the estimates are used here to investigate how knot reduction depends on the local juxtaposition structure at the strand-passage site. In particular, we observe a correlation between knot reduction and the angle of the crossing at the strand-passage site; this same angle has been shown experimentally by Neuman et al (2009 Proc. Natl Acad. Sci. USA 106 6986–91) to be important in explaining topoisomerase action on DNA. The angle of the crossing is crossing sign dependent, and, from our observations, so is knot reduction; this can be used to understand experimentally observed knot-type chirality biases.

Determinants of self-perceived health for Canadians aged 40 and older and policy implications

BackgroundPerceived health status indicates people’s overall perception of their health, including both physical and psychological dimensions. The aim of this study was to examine the determinants of self-perceived health for Canadians aged 40 and older using data from the Canadian Community Health Survey (2010).MethodsMultiple logistic regression models were employed to identify factors associated with self-perceived health in two age groups: Adults aged 65+ and Adults aged 40–64.ResultsWe found that higher income was significantly associated with better health status while chronic conditions and stress were associated with worse health status. In the 40–64 and 65+ age groups, individuals in the highest income bracket were 4.65 and 1.94 times, respectively, more likely to report better health than individuals in the lowest income bracket. The difference in the level of income associated health inequities between the two age groups point to the need for understanding the reasons behind lower inequities among seniors and how much the social protections provided by the Canadian government to seniors contribute to lowering inequities.ConclusionsThough Canada has a national public health insurance system providing coverage to all Canadians, health inequities associated with income persist providing further evidence of the importance of the social determinants of health. Examining the extent of these inequities and what factors influence them helps direct policy attention. In addition to documenting inequities, this paper discusses policy options for reducing the identified inequities.

Spatial variations in cervical cancer prevention in Colombia: Geographical differences and associated socio-demographic factors

We examined spatial variations in the frequencies of women who had not heard of human papillomavirus vaccination (NHrd-Vac) and who had not had Pap testing (NHd-Pap) among Colombian administrative divisions (departments), before and after considering differences in socio-demographic factors. Following global and local tests for clustering, Bayesian Poisson hierarchical models identified department factors associated with NHrd-Vac and NHd-Pap, as well as the extent of the spatially structured and unstructured heterogeneity. Models of spatial variations for both outcomes included the department percentage of women with subsidised health insurance. The relative risks of NHrd-Vac and NHd-Pap were highest in several departments adjacent to the Colombian border. Our finding that the risk of not having adequate access to cervical cancer (CC) prevention programmes in Colombia was location-dependent, could be used to focus resources for CC prevention programmes.

Maternal mental health: a shared care approach

BACKGROUND Maternal mental health problems affect up to 20% of women, with potentially deleterious effects to the mother and family. To address this serious problem, a Maternal Mental Health Program (MMHP) using a shared care approach was developed. A shared care approach can promote an efficient use of limited specialized maternal mental health services, strengthen collaboration between the maternal mental health care team and primary care physicians, increase access to maternal mental health care services, and promote primary care provider competence in treating maternal mental health problems. AIM The purpose of this research was to evaluate the impact of a MMHP using a shared care approach on maternal anxiety and depression symptoms of participants, the satisfaction of women and referring physicians, and whether the program met the intents of shared care approach (such as quick consultation, increased knowledge, and confidence of primary care physicians). METHODS We used a pre and post cross-sectional study design to evaluate womens depression and anxiety symptoms and the satisfaction of women and their primary care health provider with the program. Findings Depression and anxiety symptoms significantly improved with involvement with the program. Women and physicians reported high levels of satisfaction with the program. Physician knowledge and confidence treating maternal mental health problems improved. CONCLUSIONS Shared care can be an effective and efficient way to provide maternal mental health care in primary health care settings where resources are limited.

Economist intelligence unit democracy index in relation to health services accessibility: a regression analysis

BACKGROUND The relationship between political environment and health services accessibility (HSA) has not been the focus of any specific studies. The purpose of this study was to address this gap in the literature by examining the relationship between political environment and HSA. METHODS This relationship that HSA indicators (physicians, nurses and hospital beds per 10 000 people) has with political environment was analyzed with multiple least-squares regression using the components of democracy (electoral processes and pluralism, functioning of government, political participation, political culture, and civil liberties). The components of democracy were represented by the 2011 Economist Intelligence Unit Democracy Index (EIUDI) sub-scores. The EIUDI sub-scores and the HSA indicators were evaluated for significant relationships with multiple least-squares regression. RESULTS While controlling for a countrys geographic location and level of democracy, we found that two components of a nations political environment: functioning of government and political participation, and their interaction had significant relationships with the three HSA indicators. CONCLUSIONS These study findings are of significance to health professionals because they examine the political contexts in which citizens access health services, they come from research that is the first of its kind, and they help explain the effect political environment has on health.

Determinants of self-reported mental health and utilization of mental health services in Canada

ABSTRACT Research evidence suggests that the prevalence of mental health conditions in Canada has increased while a considerable percentage of people with a mental health issue do not seek professional mental health services. Weighted logistic regression models were used to determine whether age, sex, income, and education predict the self-reported mental health status of Canadians and their odds of utilizing mental health services. This study found clear disparities in reporting mental health and utilization of mental health services. Young adults (aged 25 to 44) have 1.4 times (95% CI: 1.3 to 1.6 times) higher odds of reporting poorer mental health status than seniors (aged 65 or older). Females are 2.7 times (95% CI: 2.3 to 3.1 times) more likely to utilize mental services than males. The lowest income group (<