935 resultados para alternative p-values


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Background: Urban and rural communities differ in the incidence of several diseases including coronary heart disease and some cancers. Lower hip fracture rates among rural than urban populations have been reported but few studies have compared rural and urban fractures at sites other than the hip.

Objective: To compare total and site specific fracture rates among adult residents of rural and urban communities within the same population.

Design and setting: This is a population based study on osteoporosis in Australia. All fractures occurring in adult residents over a two year period were ascertained using radiological reports. The rural and urban areas are in close proximity, with the same medical, hospital, and radiological facilities permitting uniform fracture ascertainment.

Main outcome measures: All fracture rates were age adjusted and sex adjusted to the Australian population according to the 1996 census of the Australian Bureau of Statistics and described as the rate per 10 000 person years. The p values refer to the adjusted rate difference.

Results:
The hip fracture rate (incidence per 10 000 person years) was 32% lower (39 v 57, p<0.001), and the total fracture rate 15% lower (160 v 188, p=0.004) among rural than urban residents, respectively. The lower fracture rates in the rural population were also apparent for pelvic fractures.

Conclusion:
In the older rural population, lower fracture rates at sites typically associated with osteoporosis suggest environmental factors may have a different impact on bone health in this community. If the national rate of hip fracture could be reduced to that of the rural population, the projected increase in hip fracture number attributable to aging of the population could be prevented.

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The impact of salmon farming on the environment has been widely studied; there is, however, no consensus on the magnitude and quality of these effects and little information on their extent over large salmon farming areas. Forty-three salmon farm sites of which 29 are in full operation and grouped in nine locations in southern Chile were evaluated. Using statistical methods (two-way anova), no effects were found on water column variables such as nitrate, ammonia, orthophosphate and chlorophyll, whereas they were significant on sediment variables such as nitrogen (N), phosphorus (P) and organic carbon (OC), among others. Natural variability evaluation of some parameters revealed that P in sediments had the lowest coefficient of variation (23.2%) when compared with N (65.2%), particulate organic matter (POM) (139%) and OC (39%), and showed more marked salmon farming effects with no locality effects. Four of the nine locations showed stronger effects on sediments, with average P values ranging from 150 to 230 mmol that were six to nine times higher than in control sites (25 mmol). Nitrogen and carbon in sediments, while showing significant effects on salmon farming, also showed locality effects that revealed other biogenic processes influencing sediment composition. Thus, P in sediments was proposed as a promising indicator of impact on salmon farming, although the relationship with fauna in sediments was not linear and somewhat variable; more research is therefore needed to understand such connections. Considering entire geographical locations, no relationship was found between sediment conditions under salmon cages and the condition of the water column at a farm. This may indicate the possibility of high dilution rates and recycling processes, which so far preclude the detection of more global impacts beyond the cages shadow.

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Breakfast skipping is a potentially modifiable behavior that has negative effects on health and is socioeconomically patterned. This study aimed to examine the intrapersonal (health, behavioral, and cognitive) and social factors associated with breakfast skipping. Nonpregnant women (n = 4123) aged 18-45 y from socioeconomically disadvantaged neighborhoods throughout Victoria, Australia, completed a postal questionnaire. Sociodemographic characteristics, diet, physical activity, sedentary behaviors, and cognitive and social factors were assessed by self-report. Breakfast skipping was defined in 2 ways: 1) "rarely/never" eating breakfast (n = 498) and 2) eating breakfast ≤2 d/wk (includes those who rarely/never ate breakfast; n = 865). Poisson regression was used to calculate prevalence ratios and linear trends, adjusting for covariates. The P values for linear trends are reported below. Compared with breakfast consumers, women who reported rarely/never eating breakfast tended to have poorer self-rated health (P-trend &lt; 0.001), be current smokers (P-trend &lt; 0.001), pay less attention to health (P-trend &lt; 0.001), not prioritize their own healthy eating when busy looking after their family (P-trend &lt; 0.001), have less nutrition knowledge (P-trend &lt; 0.001), and a lower proportion were trying to control their weight (P-trend &lt; 0.020). When breakfast skipping was defined as eating breakfast ≤2 d/wk, additional associations were found for having lower leisure-time physical activity (P-trend = 0.012) and less self-efficacy for eating a healthy diet (P-trend &lt; 0.043). In conclusion, a range of intrapersonal and social factors were significantly associated with breakfast skipping among women living in socioeconomically disadvantaged areas. Acknowledging the cross-sectional design and need for causal confirmation, programs that aim to promote breakfast consumption in this population group should consider targeting family-related barriers to healthy eating and nutrition knowledge.

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Ingestion of agents that modify blood buffering action may affect high-intensity performance. Here we present a meta-analysis of the effects of acute ingestion of three such agents - sodium bicarbonate, sodium citrate and ammonium chloride - on performance and related physiological variables (blood bicarbonate, pH and lactate). A literature search yielded 59 useable studies with 188 observations of performance effects. To perform the mixed- model meta-analysis, all performance effects were converted into a percentage change in mean power and were weighted using standard errors derived from exact p-values, confidence limits (CLs) or estimated errors of measurement. The fixed effects in the meta-analytic model included the number of performance-test bouts (linear), test duration (log linear), blinding (yes/no), competitive status (athiete/nonathlete) and sex (male/female). Dose expressed as buffering mmoL/kg/body mass (BM) was included as a strictly proportional linear effect interacted with all effects except blinding. Probabilistic inferences were derived with reference to thresholds for small and moderate effects on performance of 0.5% and 1.5%, respectively. Publication bias was reduced by excluding study estimates with a standard error >2.7%. The remaining 38 studies and 137 estimates for sodium bicarbonate produced a possibly mod- erate performance enhancement of 1.7% (90% CL ± 2.0%) with a typical dose of 3.5mmoL/kg/BM (-0.3g/kgIBM) in a single 1-minute sprint, following blinded consumption by male athletes. In the 16 studies and 45 estimates for sodium citrate, a typical dose of l.SmmoL/kgIBM (-0.5gIkgJBM) had an unclear effect on performance of 0.0% (±1.3%), while the five studies and six estimates for ammonium chloride produced a possibly moderate impairment of 1.6% (±1.9%) with a typical dose of 5.5mmoL/kgIBM (-0.3glkg/BM). Study and subject characteristics had the following modifying small effects on the enhancement of performance with sodium bicarbonate: an increase of 0.5% (±0.6%) with a 1 mmoL/kg/BM increase in dose; an increase of 0.6% (±0.4%) with five extra sprint bouts; a reduction of 0.6% (±0.9%) for each 10-fold increase in test duration (e.g. 1-10 minutes); reductions of 1.1% (± 1 .1%) with nonathletes and 0.7% (±1.4%) with females. Unexplained variation in effects between research settings was typically ± 1.2%. The only noteworthy effects involving physiological variables were a small correlation between performance and pre-exercise increase in blood bicarbonate with sodium bi- carbonate ingestion, and a very large correlation between the increase in blood bicarbonate and time between sodium citrate ingestion and exercise. The approximate equal and opposite effects of sodium bicarbonate and am- monium chloride are consistent with direct performance effects of pH, but sodium citrate appears to have some additional metabolic inhibitory effect. Important future research includes studies of sodium citrate ingestion several hours before exercise and quantification of gastrointestinal symptoms with sodium bicarbonate and citrate. Although individual responses may vary, we recommend ingestion of 0.3-0.5 glkg/BM sodium bicarbonate to improve mean power by 1.7% (±2.0%) in high-intensity races of short duration. ABSTRACT FROM AUTHOR

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The purpose of this study was to investigate the effectiveness of a short-duration (5-6 min, 3 d·wk) resistive exercise program with (RVE) or without (RE) whole-body vibration in reducing muscle atrophy in the lower limb during prolonged inactivity when compared with that in an inactive control group. METHODS: As part of the second Berlin BedRest Study, 24 male subjects underwent 60 d of head-down tilt bed rest. Using magnetic resonance imaging, muscle volumes of the individual muscles of the lower limb were calculated before and at various intervals during and after bed rest. Pain levels and markers of muscle damage were also evaluated during and after bed rest. Adjustment of P values to guard against false positives was performed via the false discovery rate method. RESULTS: On the "intent-to-treat" analysis, RE reduced atrophy of the medial and lateral gastrocnemius, soleus, vasti, tibialis posterior, flexor hallucis longus, and flexor digitorum longus (P ≤ 0.045 vs control group) and RVE reduced atrophy of the medial and lateral gastrocnemius and tibialis posterior (P ≤ 0.044). Pain intensity reports after bed rest were lower in RE at the foot (P ≤ 0.033) and whole lower limb (P = 0.01) and in RVE at the thigh (P ≤ 0.041), lower leg (P ≤ 0.01), and whole lower limb (P ≤ 0.036). Increases in sarcomere-specific creatine kinase after bed rest were less in RE (P = 0.020) and RVE (P = 0.020). No differences between RE and RVE were observed. CONCLUSIONS: In conclusion, a short-duration RVE or RE can be effective in reducing the effect of prolonged bed rest on lower extremity muscle volume loss during bed rest and muscle damage and pain after bed rest. Copyright © 2014 by the American College of Sports Medicine.

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BACKGROUND: Pressure injuries are a significant clinical and economic issue, affecting both patients and the health care system. Many pressure injuries in hospitals are facility acquired, and are largely preventable. Despite growing evidence and directives for pressure injury prevention, implementation of preventative strategies is suboptimal, and pressure injuries remain a serious problem in hospitals. OBJECTIVES: This study will test the effectiveness and cost-effectiveness of a patient-centred pressure injury prevention care bundle on the development of hospital acquired pressure injury in at-risk patients. DESIGN: This is a multi-site, parallel group cluster randomised trial. The hospital is the unit of randomisation. METHODS: Adult medical and surgical patients admitted to the study wards of eight hospitals who are (a) deemed to be at risk of pressure injury (i.e. have reduced mobility), (b) expected to stay in hospital for ≥48h, (c) admitted to hospital in the past 36h; and (d) able to provide informed consent will be eligible to participate. Consenting patients will receive either the pressure injury prevention care bundle or standard care. The care bundle contains three main messages: (1) keep moving; (2) look after your skin; and (3) eat a healthy diet. Nurses will receive education about the intervention. Patients will exit the study upon development of a pressure injury, hospital discharge or 28 days, whichever comes first; transfer to another hospital or transfer to critical care and mechanically ventilated. The primary outcome is incidence of hospital acquired pressure injury. Secondary outcomes are pressure injury stage, patient participation in care and health care costs. A health economic sub-study and a process evaluation will be undertaken alongside the trial. Data will be analysed at the cluster (hospital) and patient level. Estimates of hospital acquired pressure injury incidence in each group, group differences and 95% confidence interval and p values will be reported. DISCUSSION: To our knowledge, this is the first trial of an intervention to incorporate a number of pressure injury prevention strategies into a care bundle focusing on patient participation and nurse-patient partnership. The results of this study will provide important information on the effectiveness and cost-effectiveness of this intervention in preventing pressure injuries in at-risk patients. If the results confirm the utility of the developed care bundle, it could have a significant impact on clinical practice worldwide. TRIAL REGISTRATION: This trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12613001343796.

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OBJECTIVE: Low working memory (WM) is strongly linked with poor academic outcomes. WM capacity increases across childhood but how exposure to school is associated with WM development is not known. We aimed to determine extent to which chronological age and schooling duration are associated with WM at the population level. METHODS: In 2012, children in Grade 1 (the second year of formal schooling in Victoria, Australia) from 44 schools in metropolitan Melbourne were recruited. Assessments occurred over the entire school year, with schools quasi-randomly allocated to one of the 4 school terms. WM (primary outcome) was measured using 2 subtests from the computerized Automated Working Memory Assessment: Backwards Digit Recall (verbal) and Mister X (visuospatial). Linear regression was used to examine relationships of WM with time in school and age. RESULTS: Of the 1765 who provided consent, 1727 children (97.9%) had WM assessed throughout the 2012 school year. WM scores became steadily higher over the course of the year. Thus, scores were .77 and .53 SDs higher in Term 4 than Term 1 for verbal and visuospatial WM, respectively (p values for trend for both scores <.001); conclusions were unchanged when adjusted for age and potential confounders. Conversely, age associations attenuated fully once adjusted for school duration. CONCLUSIONS: Our results demonstrate, for the first time, that the developmental increases in WM are strongly associated with time spent in the classroom, above and beyond chronological age.

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AIM: To conduct a systematic review of parent and family factors associated with service use for young people with mental health problems, to inform early intervention efforts aimed at increasing service use by young people. METHODS: A systematic search of academic databases was performed. Articles were included in the review if they had: a sample of young people aged between 5 and 18 years; service use as the outcome measure; one or more parental or family variables as a predictor; and a comparison group of non-service using young people with mental health problems. In order to focus on factors additional to need, the mental health symptoms of the young person also had to be controlled for. Stouffer's method of combining P-values was used to draw conclusions as to whether or not associations between variables were reliable. RESULTS: Twenty-eight articles were identified investigating 15 parental or family factors, 7 of which were found to be associated with service use for a young person with mental health needs: parental burden, parent problem perception, parent perception of need, parent psychopathology, single-parent household, change in family structure and being from the dominant ethnic group for the United States specifically. Factors not found to be related to service use were: family history of service use, parent-child relationship quality, family functioning, number of children, parent education level, parent employment status, household income and non-urban location of residence. CONCLUSIONS: A number of family-related factors were identified that can inform effective interventions aimed at early intervention for mental health problems. Areas requiring further research were also identified.

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Background : Whilst impulsivity is most commonly linked to the development of internalizing disorders, high levels of impulsivity, anxiety, and depression have been found in detained juvenile offenders. We therefore sought to determine whether impulsivity is associated with the development of self-reported anxiety or depression in a sample of detained juvenile offenders.

Methods : 323 male juvenile offenders and 86 typically developing controls, aged 15–17 were assessed. The Schedule for Affective Disorder and Schizophrenia for School-Age Children Present and Lifetime (SADS-PL) was used to assess psychiatric diagnoses, the Barratt Impulsivity Scale (BIS-11) was used to measure impulsivity, and the Screen for Child Anxiety Related Emotional Disorders (SCARED) and the Birleson Depression Self-Rating Scale (DSRS) were used to assess self-reported anxiety and depression respectively.

Results : Compared to controls, juvenile offenders had significantly higher scores on the BIS-11 total, as well as on the motor and nonplanning subscales (all p values <0.001), as well as higher DSRS (p < 0.001) and SCARED (p < 0.05) scores. Within the juvenile offender group, scores on the SCARED correlated positively with BIS-11 total, attention subscale, motor subscale, and total DSRS (all p values <0.01). DSRS scores correlated positively with BIS-11 total, attention subscale, nonplanning subscale, and total SCARED scores (all p values <0.01). Participants were then categorized low, middle or high impulsivity according to scores on the BIS-11. One-way ANOVAs demonstrated a significant difference between these tertiles on DSRS [F(2,320) = 4.862, p < 0.05] and SCARED total scores [F(2,320) = 3.581, p < 0.05]. Specifically, post-hoc analyses found that the high impulsivity tertile scored significant higher than the remaining tertiles on both DSRS (16.1 ± 0.3 vs. 14.0 ± 0.6, p < 0.05) and SCARED (23.3 ± 0.9 vs. 18.4 ± 1.4, p < 0.05) scores. Using multiple linear regression, BIS-11 attention scores, number of months served in custody, age, and BIS-11 nonplanning scores predicted higher levels of anxiety, whilst only BIS-11 attention and nonplanning scores predicted higher levels of depression.

Conclusions : In detained juvenile offenders, high impulsivity may be an important risk factor not only for the externalizing disorders, but also for anxiety and depression. Results of this study, therefore, suggest that specific facets of impulsivity may represent one mechanism underlying the emergence of anxiety and depression in this population.

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Background

Previous reviews on risk and protective factors for violence in psychosis have produced contrasting findings. There is therefore a need to clarify the direction and strength of association of risk and protective factors for violent outcomes in individuals with psychosis.

Method

We conducted a systematic review and meta-analysis using 6 electronic databases (CINAHL, EBSCO, EMBASE, Global Health, PsycINFO, PUBMED) and Google Scholar. Studies were identified that reported factors associated with violence in adults diagnosed, using DSM or ICD criteria, with schizophrenia and other psychoses. We considered non-English language studies and dissertations. Risk and protective factors were meta-analysed if reported in three or more primary studies. Meta-regression examined sources of heterogeneity. A novel meta-epidemiological approach was used to group similar risk factors into one of 10 domains. Sub-group analyses were then used to investigate whether risk domains differed for studies reporting severe violence (rather than aggression or hostility) and studies based in inpatient (rather than outpatient) settings.

Findings

There were 110 eligible studies reporting on 45,533 individuals, 8,439 (18.5%) of whom were violent. A total of 39,995 (87.8%) were diagnosed with schizophrenia, 209 (0.4%) were diagnosed with bipolar disorder, and 5,329 (11.8%) were diagnosed with other psychoses. Dynamic (or modifiable) risk factors included hostile behaviour, recent drug misuse, non-adherence with psychological therapies (p values<0.001), higher poor impulse control scores, recent substance misuse, recent alcohol misuse (p values<0.01), and non-adherence with medication (p value <0.05). We also examined a number of static factors, the strongest of which were criminal history factors. When restricting outcomes to severe violence, these associations did not change materially. In studies investigating inpatient violence, associations differed in strength but not direction.

Conclusion

Certain dynamic risk factors are strongly associated with increased violence risk in individuals with psychosis and their role in risk assessment and management warrants further examination.

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 Introduction: Information on the epidemiology of childhood cancer in Latin America is limited. The Argentinean Oncopaediatric Registry (ROHA) is a population-based registry active since 2000. This paper describes the 3-year survival experience of children diagnosed with cancer in Argentina during 2000–2007 by major morphological subgroup, age, sex, and geographical region of residence.
Methods: Newly diagnosed paediatric cancer cases are registered in ROHA (estimated coverage is 93% of the country’s cases). Three-year overall survival was estimated using Kaplan–Meier methods. Univariate Cox models were used to compare subgroup survival.
Results: Between 2000 and 2007, a total of 10,181 new cancer diagnoses in children aged 0–14 years were reported to the registry. Three-year overall survival (95%CI) for all cancers was 61.7% (60.7; 62.7). Specific survival for the most frequent morphological types was: leukaemias 63.3% (61.6; 64.9), lymphomas and related neoplasms 75.3% (72.7; 77.7), brain neoplasms 46.3% (43.9; 48.7), soft-tissue sarcomas 52.3% (48.0; 56.5), neuroblastomas 49.6% (44.6; 54.3), renal tumours 76.7% (72.2; 80.6), and malignant bone tumours 47.2% (42.3; 51.9). Overall survival was associated with age but not sex and varied by geographical region. Compared to other regions, patients who resided in the capital city had a significantly higher survival: 69.6% (65.8; 73.0) versus 63.5% (59.4; 67.4) in Patagonia, 63.2% (61.9; 64.5) in the central region, 58.0% (54.2; 61.7) in Cuyo, 55.6% (52.5; 58.6) in the north-east, and 55.4% (52.4; 58.2) in the north-west (all P values <0.005).
Conclusions: Of children diagnosed with cancer in Argentina, 62% survived at least 3 years after diagnosis. Even though this figure is lower than that reported for more developed countries, survival patterns by diagnosis, age and sex were quite similar. Survival was lower in the two northern regions, which are areas with higher poverty levels.

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Discrepancies between classical model predictions and experimental data for deep bed filtration have been reported by various authors. In order to understand these discrepancies, an analytic continuum model for deep bed filtration is proposed. In this model, a filter coefficient is attributed to each distinct retention mechanism (straining, diffusion, gravity interception, etc.). It was shown that these coefficients generally cannot be merged into an effective filter coefficient, as considered in the classical model. Furthermore, the derived analytic solutions for the proposed model were applied for fitting experimental data, and a very good agreement between experimental data and proposed model predictions were obtained. Comparison of the obtained results with empirical correlations allowed identifying the dominant retention mechanisms. In addition, it was shown that the larger the ratio of particle to pore sizes, the more intensive the straining mechanism and the larger the discrepancies between experimental data and classical model predictions. The classical model and proposed model were compared via statistical analysis. The obtained p values allow concluding that the proposed model should be preferred especially when straining plays an important role. In addition, deep bed filtration with finite retention capacity was studied. This work also involves the study of filtration of particles through porous media with a finite capacity of filtration. It was observed, in this case, that is necessary to consider changes in the boundary conditions through time evolution. It was obtained a solution for such a model using different functions of filtration coefficients. Besides that, it was shown how to build a solution for any filtration coefficient. It was seen that, even considering the same filtration coefficient, the classic model and the one here propposed, show different predictions for the concentration of particles retained in the porous media and for the suspended particles at the exit of the media

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OBJETIVO: Determinar a acurácia das variáveis: tempo de escada (tTE), potência de escada (PTE), teste de caminhada (TC6) e volume expiratório forçado (VEF1) utilizando o consumo máximo de oxigênio (VO2máx) como padrão-ouro. MÉTODOS: Os testes foram realizados em 51 pacientes. O VEF1 foi obtido através da espirometria. O TC6 foi realizado em corredor plano de 120m. O TE foi realizado em escada de 6 lances obtendo-se tTE e PTE. O VO2máx foi obtido por ergoespirometria, utilizando o protocolo de Balke. Foram calculados a correlação linear de Pearson (r) e os valores de p, entre VO2máx e variáveis. Para o cálculo da acurácia, foram obtidos os pontos de corte, através da curva característica operacional (ROC). A estatística Kappa (k) foi utilizada para cálculo da concordância. RESULTADOS: Obteve-se as acurácias: tTE - 86%, TC6 - 80%, PTE - 71%, VEF1(L) - 67%, VEF1% - 63%. Para o tTE e TC6 combinados em paralelo, obteve-se sensibilidade de 93,5% e em série, especificidade de 96,4%. CONCLUSÃO: O tTE foi a variável que apresentou a melhor acurácia. Quando combinados o tTE e TC6 podem ter especificidade e sensibilidade próxima de 100%. Estes testes deveriam ser mais usados rotineiramente, especialmente quando a ergoespirometria para a medida de VO2máx não é disponível.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Statement of problem. Denture bases may become increasingly weaker as a result of thermal stress and flexural cyclic loading. Information regarding this potential problem and its relationship to the denture base reline is limited.Purpose. This study evaluated the influence of thermal and mechanical stresses on the strength of intact and relined denture bases.Material and methods. Twenty-eight microwave-polymerized (Acron MC) intact denture bases were prepared in the shape of a 3-mm-thick maxillary denture. Additionally, fifty-six 2-mm-thick denture bases were relined with 1 mm of autopolymerizing resin (Tokuyama Rebase Fast II or New Truliner) (n = 28). Intact and relined specimens were divided into 4 groups (n = 7) as follows: without stress (control); a mechanical stress at 0.8 Hz for 10,000 cycles; 5000 thermal cycles between 5 degrees C and 55 degrees C; or a combination thermo-mechanical stress. The specimens were vertically loaded in compression with a rounded rod at 5 mm/min until failure, using a universal testing machine. Data on maximum fracture load (N), deflection at fracture (%), and fracture energy (N-mm) were analyzed by 2-way analysis of variance and Student-Newman-Keuls tests (alpha = .05).Results. The strength of the denture bases relined with New Truliner was not significantly affected by any of the experimental conditions, but comparing the control groups, New Truliner exhibited the lowest maximum fracture load values. The maximum fracture load of intact denture bases (P = .002) and those relined with Tokuyama Rebase Fast II (P = .01) showed a significant decrease after thermal stress. Additionally, cyclic loading significantly decreased the maximum fracture load (P < .001), deflection at fracture (P = .025), and fracture energy (P < .001) of intact denture bases and those relined with Tokuyama Rebase (P values of .002, .039, and .001, respectively).Conclusion. Thermal and mechanical stresses exert deleterious effects on the strength of intact and/or relined denture bases, which vary according to the relining material used.