Multistate life tables using Stata

2020 ◽  
Vol 20 (3) ◽  
pp. 721-745
Author(s):  
Jerônimo Oliveira Muniz
Keyword(s):  
Life Table ◽  
Input Data ◽  
Average Duration ◽  
Transition Rates ◽  
Absorbing State ◽  
Multistate Life Tables ◽  
The Mean ◽  
Time Specific ◽  
Number Of Individuals ◽  
Multistate Life Table

The mslt command calculates the functions of a multistate life table and plots a graph of conditional and unconditional life expectancies by time. The command provides linear and exponential solutions to estimate the number of individuals, transitions, probabilities, person-years, and years of life in a given cohort and state of occupancy. The input data are time-specific transition rates (or survivorship proportions) between nonabsorbing and at most one absorbing state. In addition to the mean age at transfer between states, mslt calculates the following summary measures: the mean age, the probability of dying, the average duration, and the proportion of life spent in a specific state.

Multistate Life Tables: Movement versus Transition Perspectives

1980 ◽  
Vol 12 (5) ◽  
pp. 533-562 ◽  
Author(s):  
J Ledent
Keyword(s):  
Life Table ◽  
Principal Part ◽  
Life Tables ◽  
Ordinary Life ◽  
Multistate Life Tables ◽  
Versus Transition ◽  
Alternative Approaches ◽  
The One ◽  
Transition Approach ◽  
Multistate Life Table

This paper attempts to present a comprehensive view of the methodological and empirical aspects involved in the construction of increment–decrement life tables, that is life tables which allow entries into (increments) as well as withdrawals from (decrements) alternative states. The first principal part of the paper, section 2, presents a theoretical exposition of such tables, paralleling that of the ordinary life table, and discusses various issues raised by the conceptualization of multistate life-table functions. The second principal part, section 3, contrasts the two alternative approaches to the applied calculation of such tables. On the one hand, the movement approach, which views interstate transfers as events (such as deaths or births), requires data in the form of occurrence/exposure rates; on the other hand, the transition approach, which regards such transfers as the results of a change in an individual's state of presence between two points in time, uses data in the form of survivorship proportions.

On the relationship between µ-invariant measures and quasi-stationary distributions for continuous-time Markov chains

1993 ◽  
Vol 25 (01) ◽  
pp. 82-102
Author(s):  
M. G. Nair ◽  
P. K. Pollett
Keyword(s):  
Invariant Measure ◽  
Stationary Distribution ◽  
Continuous Time ◽  
Sufficient Condition ◽  
Transition Rates ◽  
Necessary And Sufficient Condition ◽  
Absorbing State ◽  
Necessary And Sufficient ◽  
Forward Equations ◽  
Quasi Stationary Distribution

In a recent paper, van Doorn (1991) explained how quasi-stationary distributions for an absorbing birth-death process could be determined from the transition rates of the process, thus generalizing earlier work of Cavender (1978). In this paper we shall show that many of van Doorn's results can be extended to deal with an arbitrary continuous-time Markov chain over a countable state space, consisting of an irreducible class, C, and an absorbing state, 0, which is accessible from C. Some of our results are extensions of theorems proved for honest chains in Pollett and Vere-Jones (1992). In Section 3 we prove that a probability distribution on C is a quasi-stationary distribution if and only if it is a µ-invariant measure for the transition function, P. We shall also show that if m is a quasi-stationary distribution for P, then a necessary and sufficient condition for m to be µ-invariant for Q is that P satisfies the Kolmogorov forward equations over C. When the remaining forward equations hold, the quasi-stationary distribution must satisfy a set of ‘residual equations' involving the transition rates into the absorbing state. The residual equations allow us to determine the value of µ for which the quasi-stationary distribution is µ-invariant for P. We also prove some more general results giving bounds on the values of µ for which a convergent measure can be a µ-subinvariant and then µ-invariant measure for P. The remainder of the paper is devoted to the question of when a convergent µ-subinvariant measure, m, for Q is a quasi-stationary distribution. Section 4 establishes a necessary and sufficient condition for m to be a quasi-stationary distribution for the minimal chain. In Section 5 we consider ‘single-exit' chains. We derive a necessary and sufficient condition for there to exist a process for which m is a quasi-stationary distribution. Under this condition all such processes can be specified explicitly through their resolvents. The results proved here allow us to conclude that the bounds for µ obtained in Section 3 are, in fact, tight. Finally, in Section 6, we illustrate our results by way of two examples: regular birth-death processes and a pure-birth process with absorption.

Inoptimality losses in forest management decisions caused by errors in an inventory based on airborne laser scanning and aerial photographs

2010 ◽  
Vol 40 (12) ◽  
pp. 2427-2438 ◽  
Author(s):  
Md. Nurul Islam ◽  
Mikko Kurttila ◽  
Lauri Mehtätalo ◽  
Timo Pukkala
Keyword(s):  
Input Data ◽  
Laser Scanning ◽  
Basal Area ◽  
Airborne Laser Scanning ◽  
Aerial Photographs ◽  
Stand Age ◽  
Inventory Data ◽  
Airborne Laser ◽  
Mean Diameter ◽  
The Mean

Errors in inventory data may lead to inoptimal decisions that ultimately result in financial losses for forest owners. We estimated the expected monetary losses resulting from data errors that are similar to errors in laser-based forest inventory. The mean loss was estimated for 67 stands by simulating 100 realizations of inventory data for each stand with errors that mimic those in airborne laser scanning (ALS) based inventory. These realizations were used as input data in stand management optimization, which maximized the present value of all future net incomes (NPV). The inoptimality loss was calculated as the difference between the NPV of the optimal solution and the true NPV of the solution obtained with erroneous input data. The results showed that the mean loss exceeded €300·ha–1 (US$425·ha–1) in 84% of the stands. On average, the losses increased with decreasing stand age and mean diameter. Furthermore, increasing errors in the basal area weighted mean diameter and basal area of spruce were found to significantly increase the loss. It has been discussed that improvements in the accuracy of ALS-based inventory could be financially justified.

Sporadic Schwannomatosis: A Systematic Review Following the 2005 Consensus Statement

2018 ◽  
Vol 79 (05) ◽  
pp. 408-415 ◽  
Author(s):  
Jan Victor ◽  
Thibault Poujade ◽  
Nadine Hollevoet ◽  
Gregoire Chick
Keyword(s):  
Systematic Review ◽  
Consensus Statement ◽  
Case Reports ◽  
Case Series ◽  
Spinal Tumors ◽  
The Mean ◽  
Tumor Distribution ◽  
Key Aspects ◽  
Number Of Individuals

Aims To identify the frequency of reports of sporadic schwannomatosis, the types of patients affected, and the nerves affected. Patients and Methods We identified all case reports and case series that reported on patients with sporadic schwannomatosis according to established criteria. Results The initial search yielded 1,597 studies, of which 15 were included. A total of 38 of 55 individuals met the inclusion criteria. The mean age of the patients was 48 years; 41% were male. Thirty-three patients had peripheral nerve tumors, and 17 had spinal tumors. Twelve had tumors in both locations. Tumor distribution was unilateral in 25 of 30 cases (83.3%) and segmental (limited to one limb or five or fewer contiguous segments of the spine) in 28 of 38 cases (73.7%). Conclusion This systematic review quantified the number of individuals who meet the criteria for sporadic schwannomatosis and better described this population to facilitate the classification of neurofibromatosis in regard to the 2005 consensus statement. Unilateral or segmental distribution of nerve tumors are key aspects when dealing with multiple noncutaneous schwannomas without involvement of the vestibular nerve.

scholarly journals Evaluation of the efficacy of neonicotinoid and pyrethroid insecticides in Diaphorina citri Kuwayama (Hemiptera: Liviidae) populations in Colombia

2018 ◽  
Vol 12 (2) ◽  
pp. 358-368
Author(s):  
Augusto Ramírez-Godoy ◽  
Gina Puentes-Pérez ◽  
Hermann Restrepo-Díaz
Keyword(s):  
Tropical Dry Forest ◽  
Dry Forest ◽  
Asian Citrus Psyllid ◽  
Insect Vector ◽  
Diaphorina Citri ◽  
Pyrethroid Insecticides ◽  
Lambda Cyhalothrin ◽  
The Mean ◽  
Number Of Individuals ◽  
Forest Conditions

The Asian citrus psyllid Diaphorina citri is the insect vector of the disease known as huanglongbing (HLB), which is the most devastating disease of citrus crops in the world. The Asian citrus psyllid was officially reported in Colombia in 2007, and a national phytosanitary emergency was declared because of the presence of HLB in 2015. Two different experiments were carried out in two locations (Apulo and Jerusalén, Department of Cundinamarca) in Colombia to evaluate the effectiveness of neonicotinoid (clothianidin, imidacloprid and thiamethoxan) and pyrethroid applications (bifenthrin, deltamethrin and lambda cyhalothrin) on the control of D. citri populations (adults, nymphs and eggs) in ‘Tahiti’ lime trees established under tropical dry forest conditions. In the first experiment, trees were foliarly treated as follows: (1) untreated trees; (2) trees treated with 100 g ha-1 of imidacloprid; (3) trees treated with 60 g ha-1 of bifenthrin; (4) trees treated with 12.5 g ha-1 of deltamethrin and (5) trees treated with a co-formulation of 70 g ha-1 of a neonicotinoid (thiametoxan) and 53 g ha-1 of a pyrethroid (lambda cyhalothrin). In the second experiment, trees were treated with 100 g ha-1 of clothianidin. Foliar insecticide applications were carried out at 0 and 4 weeks after the initiation of treatments (WAT). In the first trial, the control presented a mean number of individuals per flush of ≈1.14, whereas the trees treated with neoinicotinoids and pyrethroids showed 50% fewer individuals (0.53-0.61). For the population of immatures, the number of nymphs was 2.25 nymphs per flush in the control, as compared to 0.82-1.22 individuals observed in the treatments with insecticides. The mean number of eggs was also between 80-100% higher in the control trees (2.37 individuals), as compared to the treated trees (1.14-1.78). In the second trial, the use of clothianidin showed a higher control of eggs. The results suggest that the rotation of neonicotinoids with pyrethroids can be a tool to reduce populations and delay resistance processes in D. citri in citrus trees established under tropical dry forest conditions in Colombia.

scholarly journals Long-term species richness-abundance dynamics in relation to species departures and arrivals in wintering urban bird assemblages

2019 ◽  
Vol 5 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Jukka Suhonen ◽  
Jukka Jokimäki
Keyword(s):  
Species Richness ◽  
Bird Species ◽  
Total Abundance ◽  
Bird Species Richness ◽  
Abundance Dynamics ◽  
Local Species Richness ◽  
Local Species ◽  
The Mean ◽  
Urban Bird ◽  
Number Of Individuals

Abstract Temporal dynamics of local assemblages depend on the species richness and the total abundance of individuals as well as local departure and arrival rates of species. We used urban bird survey data collected from the same 31 study plots and methods during three winters (1991–1992; 1999–2000 and 2009–2010) to analyze the temporal relationship between bird species richness and total number of individuals (abundance). We also evaluated local departures and arrivals of species in each assemblage. In total, 13,812 individuals of 35 species were detected. The temporal variation in bird species richness followed the variation in the total number of individuals. The numbers of local departure and arrival events were similar. Also, the mean number of individuals of the recently arrived species (8.6) was almost the same as the mean number of individuals of the departed species (8.2). Risk of species departure was inversely related to number of individuals. Local species richness increased by one species when the total abundance of individuals increased by around 125 individuals and vice versa. Our results highlight the important role of local population departures and arrivals in determining the local species richness-abundance dynamics in human-dominated landscapes. Local species richness patterns depend on the total number of individuals as well as both the departure-arrival dynamics of individual species as well as the dynamics of all the species together. Our results support the more individuals hypothesis, which suggests that individual-rich assemblages have more species.

scholarly journals Biology and life-table of Typhlodromus (Anthoseius) athenas (Acari: Phytoseiidae) fed with the Old World Date Mite, Oligonychus afrasiaticus (Acari: Tetranychidae)

Acarologia ◽  
2018 ◽  
Vol 58 (1) ◽  
pp. 52-61
Author(s):  
Samah Ben Chaaban ◽  
Brahim Chermiti ◽  
Serge Kreiter
Keyword(s):  
Life Table ◽  
Intrinsic Rate ◽  
Phoenix Dactylifera ◽  
Reproductive Rate ◽  
Intrinsic Rate Of Increase ◽  
Net Reproductive Rate ◽  
Old World ◽  
Rate Of Increase ◽  
Wide Range ◽  
The Mean

The old world date mite Oligonychus afrasiaticus is an important spider mite pest of the date palms Phoenix dactylifera L. mostly in North Africa and the Middle East. A population of the predaceous mite Typhlodromus (Anthoseius) athenas has been recently found in Tunisia in association with a decrease of O. afrasiaticus densities. The objective of this paper was to assess the development and reproduction abilities of T. ( A.) athenas on O. afrasiaticus under laboratory conditions at two temperatures: 27 and 32 °C. The results obtained show that females of T. (A.) athenas develop in 5 days at 27 °C and 4.1 days at 32 °C. The mean fecundity of T. (A.) athenas was 32.1 and 23.2 eggs per female at 27 and 32 °C, respectively. Life table parameters were stimated: the net reproductive rate (Ro) 27.9 and 17.9 eggs/female, the intrinsic rate of increase (rm) 0.322 and 0,344 female/female/day and the mean generation time (T) 10.3 and 8.4 days at 27 and 32 °C, respectively. At both temperatures tested, T. (A.) athenas intrinsic rate of increase was greater than that of O. afrasiaticus (rm = 0.213 at 32 °C,against rm = 0.166 day1 at 27 °C). Typhlodromus (A.) athenas would be able to develop at a wide range of temperatures feeding on O. afrasiaticus and seems to be able to potentially control it.

scholarly journals Haematological and Haemostatic Changes Associated with Major Depressive Disorder among Nigerians.

2021 ◽  
Vol 5 (2) ◽  
pp. 238-245
Author(s):  
Oloruntoba A. Ekun
Keyword(s):  
Major Depressive Disorder ◽  
Depressive Disorder ◽  
Sodium Citrate ◽  
Red Cell ◽  
Major Depressive ◽  
Red Cell Indices ◽  
Healthy Control ◽  
The Mean ◽  
Number Of Individuals ◽  
Apparently Healthy

Background: A link between major depressive disorder (MDD) and haematological as well as co-agulation disorders has been postulated. This study aims to evaluate haematological and haemostatic changes among Nigerians with major depressive disorder Methods: Two hundred volunteers consisting of an equal number of individuals diagnosed with major depressive disorder (MDD) based on DMS-IV criteria and apparently healthy control participated in this study. The blood sample was collected into tri-sodium citrate K2EDTA bottles respectively and was evaluated for some haemostatic parameters , using ELISA, Clauss, Quick’s One Stage, Proctor and Rapaport’s methods. Results: The mean WBC, hemoglobin and differential lymphocyte were significantly higher among MDD total volunteers (p < 0.001). The red cell indices and platelet count were lower among MDD (p <0.001). Also the prothrombin time (PT), fibrinogen, protein-C and erythrocytes sedimentation rate (ESR) were all raised (p <0.001) among volunteers with MDD. Positive associations existed be-tween MCV and RBC (r: 0.364; p<0.001), PT and APTT (r: 0.319 p <0.001), APTT and fibrinogen (r: 0.239, p = 0.017) as well as PT and fibrinogen (r: 0.275 p = 0.006) at 95% confidence interval. Conclusion: Changes in total leucocytes count, lymphocytes values and haemostatic parameters among volunteers with depression may impacts deleterious effects on the immune response as well as haemostatic homeostasis, while decreased red cell indices may suggest occult nutritional anaemia.

scholarly journals National survey of Canadian residents and program directors regarding parental leave during residency

2020 ◽  
Author(s):  
Karen Willoughby ◽  
Marie Julien ◽  
Benjamin Rich Zendel ◽  
Vernon Curran
Keyword(s):  
Return To Work ◽  
Residency Program ◽  
Parental Leave ◽  
Average Duration ◽  
Program Directors ◽  
Work Hours ◽  
Medical Resident ◽  
The Mean ◽  
Almost All ◽  
Residency Program Directors

Background: Despite the advantages of having a child as a medical resident, the transition back to residency after parental leave can be challenging. This study is the first to investigate this issue using a nation-wide Canadian sample of both residents and program directors. Method: A questionnaire was developed and made available online. Respondents included 437 female residents, 33 male residents, and 172 residency program directors. The mean length of parental leave was nine months for female residents and six weeks for male residents. Almost all female residents (97.5%) breastfed with an average duration of 12 months. The top challenges reported by residents were feeling guilty for being away from their family, long and unpredictable work hours, sleep deprivation, and finding time to study. When female residents and program directors were matched to both school and program (N = 99 pairs), there was no difference in the total number of challenges reported, but program directors reported offering significantly more accommodations than female residents reported being offered, t(196) = 13.06, p < .001. Results: Our data indicate there is a need for better communication between resident parents and program directors, as well as clear program-specific parental leave policies, particularly for supporting breastfeeding mothers as they return to work.

scholarly journals A formula for expressing the decrement of human life. In a letter addressed to Sir Edward Hyde East, Bart. M. P. F. R. S. By Thomas Young, M. D. For. Sec. R. S

1833 ◽  
Vol 2 ◽  
pp. 275-276
Keyword(s):  
Average Duration ◽  
Human Life ◽  
Annual Average ◽  
Prolongation Of Life ◽  
The Mean ◽  
Full Life ◽  
One Year

The author first observes that an opinion is generally prevalent, of a decided increase in the average duration of human life in many parts of Europe ; but he yet regards it as probable that this improvement has been much exaggerated, partly on account of the limited number of persons on whom the observations have been made, and partly from erroneous views respecting the profits of assurance companies. He then examines the evidence on which this opinion rests, and gives a comparative statement of the annual average of mortality, the mean term of full life, and the mean age of mankind, according to a great number of different authorities ; and considers that a prolongation of life to the extent of one year in eight, is a much fairer estimate than one in three, which some have maintained, even on the limited grounds of the experience on which they have reasoned.

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