Mortality, wastage, and lifetime productivity of Bos indicus cows under extensive grazing in northern Australia. 1. Seasonal mating in the speargrass region

1995 ◽  
Vol 35 (3) ◽  
pp. 285 ◽  
Author(s):  
PK O'Rourke ◽  
G Fordyce ◽  
RG Holroyd ◽  
ID Loxton
Keyword(s):  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Bos Indicus ◽  
Herd Size ◽  
Northern Australia ◽  
Hazards Model ◽  
Specific Mortality ◽  
Wastage Rate ◽  
Very High ◽  
Genotype Effects

Mortality and wastage rates and lifetime productivity for seasonally mated, Bos indicus cows were studied over 8000 cow year records from 1972 to 1992 at Swan's Lagoon in the subcoastal speargrass region of North Queensland. The proportional hazards model was used to estimate age-specific mortality and wastage rates, adjusted for cohort and genotype effects. The 1970-72 cohorts had an average mortality of 1.7% (range 0-4.2%), with this low overall rate tending to increase with age. The average mortality rate for the 1973-87 cohorts was 1.2% (range 0.5-2.6%), with no pattern with age. For 1970-72 cohorts, the average wastage rate was 8.9% and ranged from 2.1 to 18.3% with no clear age pattern. However, there was a clear age pattern for the 1973-87 cohorts, with an average wastage rate of 9.2% comprising very high rates (27.5%) for 2-year-olds and low rates (2.8-8.9%) for 3-7-year-olds, increasing to 11.9% for 8-year-olds and 14.2% for 9-year-olds. The heifer replacement rates to maintain a stable herd size were 17.5 and 19.2% for the 2 herds. Lifetime productivity was very low, with 1970-72 cohorts rearing 3.3 calves over 4.7 years at a rate of 57.5% calves per year, and 1973-87 cohorts rearing 3.1 calves over 4.9 years at a rate of 45.0% calves per year. Total weaner weights reared up to 10 years of age were 578 kg for 1970-72 cohorts and 315 kg for 1973-87 cohorts. However, variability between individual cows was high, indicating scope for selection based on productivity, provided that better performing cows can be identified from predictors early in life.

Mortality, wastage, and lifetime productivity of Bos indicus cows under extensive grazing in northern Australia. 2. Continuous mating in the semi-arid tropics

1995 ◽  
Vol 35 (3) ◽  
pp. 297 ◽  
Author(s):  
PK O'Rourke ◽  
RM Sullivan ◽  
JA Neale
Keyword(s):  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Bos Indicus ◽  
Herd Size ◽  
Replacement Rate ◽  
Hazards Model ◽  
Wastage Rate ◽  
Breeding Herd ◽  
North Western ◽  
Semi Arid

Mortality and wastage rates and lifetime productivity were studied over 4800 cow years from 1981 to 1990 with continuous mating and minimal management in the semi-arid tropics at Kidman Springs, Northern Territory. The proportional hazards model was used to estimate age-specific mortality and wastage rates, adjusted for cohort effects. Annual breeder mortality rate averaged 11.5%, with similar rates in the range 9.0-12.0% for 2-9-year olds, increasing to 15.5% for 10-year-olds, 17.9% for 11-year-olds, and >20% for older cows. A further 20.8% of the cows that calved failed to rear the calf to branding. Wastage included mortalities and physical culls but minimal discretionary culls based on reproductive performance or maximum age. The wastage rate averaged 16.7%, ranged from 11.1 to 14.4% for 2-9-year-olds, increased to 21.1% for 10-year-olds and 34.3% for 11-year-olds, and exceeded 50% for older cows. The heifer replacement rate to maintain a stable herd size was 16.3%. Typical lifetime productivity up to 10 years of age in this harsh north-western environment was 3.1 calves reared over a lifetime of 6.5 years in the breeding herd, at a rate of 44.5% calves per year. Timing of first pregnancy was identified as a useful predictor of lifetime productivity when overall productivity was low. Cows that were lactating as 2-year-olds reared 4.0 calves in their lifetime up to 10 years of age, cows pregnant at this age reared 3.2 calves, and non-pregnant cows reared only 2.6 calves.

scholarly journals Prediagnosis plasma concentrations of enterolactone and survival after colorectal cancer: the Danish Diet, Cancer and Health cohort

2018 ◽  
Vol 122 (5) ◽  
pp. 552-563 ◽  
Author(s):  
Cecilie Kyrø ◽  
Kirsten Frederiksen ◽  
Marianne Holm ◽  
Natalja P. Nørskov ◽  
Knud E. B. Knudsen ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Plasma Concentrations ◽  
Cox Proportional Hazards ◽  
Cox Proportional Hazards Model ◽  
Limited Attention ◽  
Hazards Model ◽  
Specific Mortality ◽  
Cancer Specific Mortality

AbstractThe association between lifestyle and survival after colorectal cancer has received limited attention. The female sex hormone, oestrogen, has been associated with lower colorectal cancer risk and mortality after colorectal cancer. Phyto-oestrogens are plant compounds with structure similar to oestrogen, and the main sources in Western populations are plant lignans. We investigated the association between the main lignan metabolite, enterolactone and survival after colorectal cancer among participants in the Danish Diet, Cancer and Health cohort. Prediagnosis plasma samples and lifestyle data, and clinical data from time of diagnosis from 416 women and 537 men diagnosed with colorectal cancer were used. Enterolactone was measured in plasma using a liquid chromatography–tandem mass spectrometry (LC–MS/MS) method. Participants were followed from date of diagnosis until death or end of follow-up. During this time, 210 women and 325 men died (170 women and 215 men died due to colorectal cancer). The Cox proportional hazards model was used to estimate hazard ratios (HR) and 95 % CI. Enterolactone concentrations were associated with lower colorectal cancer-specific mortality among women (HRper doubling: 0·88, 95 % CI 0·80, 0·97, P=0·0123). For men, on the contrary, enterolactone concentrations were associated with higher colorectal cancer-specific mortality (HRper doubling: 1·10, 95 % CI 1·01, 1·21, P=0·0379). The use of antibiotics affects enterolactone production, and the associations between higher enterolactone and lower colorectal cancer-specific mortality were more pronounced among women who did not use antibiotics (analysis on a subset). Our results suggest that enterolactone is associated with lower risk of mortality among women, but the opposite association was found among men.

Protective Effects of Familial Longevity Decrease with Age and Become Negligible for Centenarians

2021 ◽  
Author(s):  
Natalia S Gavrilova ◽  
Leonid A Gavrilov
Keyword(s):  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Cox Proportional Hazards ◽  
Cox Proportional Hazards Model ◽  
Lower Mortality ◽  
Protective Effects ◽  
Hazards Model ◽  
Specific Mortality ◽  
Theory Of Aging ◽  
Familial Longevity

Abstract It is known that biological relatives of long-lived individuals demonstrate lower mortality and longer lifespan compared to relatives of shorter-lived individuals, and at least part of this advantage is likely to be genetic. Less information, however, is available about effects of familial longevity on age-specific mortality trajectories. We compared mortality patterns after age 50 years for 10,045 siblings of U.S. centenarians and 12,308 siblings of shorter-lived individuals (died at age 65 years). Similar comparisons were made for sons and daughters of longer-lived parents (both parents lived 80 years and more) and shorter-lived parents (both parents lived less than 80 years) within each group of siblings. Although relatives of longer-lived individuals have lower mortality at younger ages compared to relatives of shorter lived individuals, this mortality advantage practically disappears by age 100 years. To validate this observation further, we analyzed survival of 3,408 U.S. centenarians born in 1890-97 with known information on maternal and paternal lifespan. We found using the Cox proportional hazards model that both maternal and paternal longevity (lifespan 80+ years) is not significantly associated with survival after age 100 years. The results are compatible with the predictions of reliability theory of aging suggesting higher initial levels of system redundancy (reserves) in individuals with protective familial/genetic background and hence lower initial mortality. Heterogeneity hypothesis is another possible explanation for the observed phenomena.

Factors influencing prostate cancer specific mortality in patients receiving delayed androgen deprivation therapy for metastasis after biochemical recurrence following radical prostatectomy

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 4571-4571 ◽  
Author(s):  
D. V. Makarov ◽  
B. J. Trock ◽  
E. B. Humphreys ◽  
L. A. Mangold ◽  
M. A. Carducci ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Cox Proportional Hazards ◽  
Cox Proportional Hazards Model ◽  
Failure Times ◽  
Factors Influencing ◽  
Hazards Model ◽  
Psa Failure ◽  
Specific Mortality

4571 Background: For men developing PSA failure after radical prostatectomy (RP), administration of immediate androgen deprivation therapy (ADT) has not been shown to improve survival compared to delaying ADT until evidence of metastatic disease. We evaluated factors influencing prostate cancer (PCa) specific mortality (PCSM) in a cohort of PSA era patients developing metastases after RP treated with delayed ADT. Methods: 3,658 men had RP by a single surgeon at Johns Hopkins Hospital from 4/82 until 6/05. 553 had PSA failure. 216 developed radiographically evident distant metastasis. Of these, 91 men formed the study cohort: initially treated during the PSA era (1987–2005), received ADT only after documented metastasis, and having complete data. 41 of these men died. Median failure times were estimated with the Kaplan-Meier method. Prognostic impact was estimated as the hazard ratio (HR) derived from the Cox proportional hazards model. Results: Median followup from RP was 10 yrs (range 2–18). Actuarial median failure times are: 1 yr from RP to PSA failure (range 1–11), 32 mos from PSA failure to metastasis (range 0–129), 79 mos from metastasis to death (range 7–181), and 13 yrs from RP to death (range 2–18). The following variables were significant prognostic factors for PCSM in univariate analyses: Pain at diagnosis of metastases (p < 0.01), time from RP to metastasis (p = 0.02), hematocrit at metastasis (p < 0.01) and PSADT <3 mos during the 2 years prior to metastasis (p < 0.01). A multivariable Cox proportional hazards model demonstrated the following independent predictors of PCSM: pain (HR = 10.5 p < 0.01), PSA at metastasis ≥100 ng/mL (HR = 5.3 p < 0.01) and PSADT < 3 months (HR = 7.1 p < 0.01). PSADT determined in the two years immediately after PSA failure (HR = 1.0 p = 0.37) and time from RP to bone metastasis (HR = 1.0 p = 0.80) were not independent predictors of PCSM. Conclusion: Men receiving delayed ADT for development of metastasis after RP may have a prolonged survival time (13 yrs post RP - range 2–18). Optimizing the time for ADT in these patients requires well-designed, prospective randomized studies. Our data may facilitate the selection of patients and thresholds for implementation of ADT. No significant financial relationships to disclose.

HRA Model for Hypercholesterolemia Based on a Longitudinal Health Database

1998 ◽  
Vol 37 (02) ◽  
pp. 130-133
Author(s):  
T. Kishimoto ◽  
Y. Iida ◽  
K. Yoshida ◽  
M. Miyakawa ◽  
H. Sugimori ◽  
...  
Keyword(s):  
Total Cholesterol ◽  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Model Analysis ◽  
Serum Total Cholesterol ◽  
Hazards Model ◽  
The Mean ◽  
Health Database ◽  
Observation Period

AbstractTo evaluate the risk factors for hypercholesterolemia, we examined 4,371 subjects (3,207 males and 1,164 females) who received medical checkups more than twice at an AMHTS in Tokyo during the period from 1976 through 1991; and whose serum total cholesterol was under 250 mg/dl. The mean follow-up duration was 6.6 years. A self-registering questionnaire was administered at the time of the health checkup. The endpoint of this study was the onset of hypercholesterolemia when the level of serum total cholesterol was 250 mg/dl and over. We compared two prognosis groups (normal and hypercholesterol) in terms of age, examination findings and lifestyle. After assessing each variable, we employed Cox's proportional hazards model analysis to determine the factors related to the occurrence of hypercholesterolemia. According to proportional hazards model analysis, total cholesterol, triglyceride and smoking at the beginning, and hypertension during the observation period were selected in males; and total cholesterol at the beginning and age were selected in females to determine the factors related to the occurrence of hypercholesterolemia.

Correlates of Child Mortality in Pakistan: A Hazards Model Analysis

1999 ◽  
Vol 38 (1) ◽  
pp. 85-118 ◽  
Author(s):  
Jennifer Benneti
Keyword(s):  
Child Mortality ◽  
Proportional Hazards ◽  
Contraceptive Use ◽  
Proportional Hazards Model ◽  
Economic Status ◽  
Model Analysis ◽  
Health Seeking ◽  
Large Cities ◽  
Number Of Children ◽  
Hazards Model

This study investigated factors associated with child mortality in an area in Rawalpindi, one of the large cities of Pakistan. Using both demographic and anthropological methods, the research was conducted to specifically examine the processes and mechanisms whereby a link is established between child mortality and its covariates. Controlling for the socio-economic status as a determinant of child mortality, the study population was limited to a lower income stratum living in a homogeneous environment where all households had equal access to health-related and other facilities. Results of the proportional hazards model analysis on 130I index children suggest that non-economic factors like maternal health-seeking behaviour were related to high child mortality. The cultural norm of bearing a large number of children was the most significant correlate. In order of significance, this was followed by contraceptive use, current age of the mother, age at marriage and the hygienic conditions of the household. The study provides strong evidence of familial clustering of mortality by order of the household.

scholarly journals Risk factors associated with major adverse cardiac and cerebrovascular events following percutaneous coronary intervention: a 10-year follow-up comparing random survival forest and Cox proportional-hazards model

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Maryam Farhadian ◽  
Sahar Dehdar Karsidani ◽  
Azadeh Mozayanimonfared ◽  
Hossein Mahjub
Keyword(s):  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Coronary Intervention ◽  
Cox Proportional Hazards ◽  
Cox Proportional Hazards Model ◽  
Hazards Model ◽  
Cerebrovascular Events ◽  
Long Term Follow Up ◽  
Stent Length

Abstract Background Due to the limited number of studies with long term follow-up of patients undergoing Percutaneous Coronary Intervention (PCI), we investigated the occurrence of Major Adverse Cardiac and Cerebrovascular Events (MACCE) during 10 years of follow-up after coronary angioplasty using Random Survival Forest (RSF) and Cox proportional hazards models. Methods The current retrospective cohort study was performed on 220 patients (69 women and 151 men) undergoing coronary angioplasty from March 2009 to March 2012 in Farchshian Medical Center in Hamadan city, Iran. Survival time (month) as the response variable was considered from the date of angioplasty to the main endpoint or the end of the follow-up period (September 2019). To identify the factors influencing the occurrence of MACCE, the performance of Cox and RSF models were investigated in terms of C index, Integrated Brier Score (IBS) and prediction error criteria. Results Ninety-six patients (43.7%) experienced MACCE by the end of the follow-up period, and the median survival time was estimated to be 98 months. Survival decreased from 99% during the first year to 39% at 10 years' follow-up. By applying the Cox model, the predictors were identified as follows: age (HR = 1.03, 95% CI 1.01–1.05), diabetes (HR = 2.17, 95% CI 1.29–3.66), smoking (HR = 2.41, 95% CI 1.46–3.98), and stent length (HR = 1.74, 95% CI 1.11–2.75). The predictive performance was slightly better by the RSF model (IBS of 0.124 vs. 0.135, C index of 0.648 vs. 0.626 and out-of-bag error rate of 0.352 vs. 0.374 for RSF). In addition to age, diabetes, smoking, and stent length, RSF also included coronary artery disease (acute or chronic) and hyperlipidemia as the most important variables. Conclusion Machine-learning prediction models such as RSF showed better performance than the Cox proportional hazards model for the prediction of MACCE during long-term follow-up after PCI.

scholarly journals Influence of Tourism Seasonality and Financial Ratios on Hotels’ Exit Risk

2021 ◽  
pp. 109634802110160
Author(s):  
Dengjun Zhang ◽  
Jinghua Xie
Keyword(s):  
Proportional Hazards ◽  
Proportional Hazards Model ◽  
Hotel Industry ◽  
Financial Ratios ◽  
Market Segment ◽  
Tourism Demand ◽  
Hazards Model ◽  
Two Measures ◽  
The Impact

Tourism seasonality negatively affects hotels’ operational and financial performance and then survival probabilities. Several studies have evaluated the impact of tourism seasonality on hotels’ exit risk. However, the empirical findings are ambiguous, probably due to the overall seasonality and different measures used in these studies. Against this background, this study explores the impact of tourism seasonality on hotel firms’ exit risk, using a proportional hazards model. We controlled for financial ratios, the main factors influencing the exit risk, and used two measures of tourism seasonality by market segment, namely, leisure, business, and conference tourism. The case study is the Norwegian hotel industry. The empirical results suggest that the different seasonal patterns of tourism demand in the market segments mitigate the impact of the overall seasonality on hotels’ exit risk, and that seasonality measures of various tourism segments affect the exit risk in different ways.

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