Name: life tables and survival patterns
Uploaded: 2025-01-09T15:14:16.000Z
Duration: 1 min 22 s
Channel: JoVE

K12 Standards

Texas Essential Knowledge and Skills

High School

Physics

PHYS.1

PHYS.1.F

Life Tables

Una tavola di vita o una tavola di mortalità rappresenta i modelli di sopravvivenza di una popolazione.
Comprende più colonne, ognuna delle quali ha uno scopo pratico, a partire dagli intervalli di tempo nella prima colonna.
La seconda colonna elenca il numero di individui, pazienti o soggetti all'inizio dello studio e la terza colonna elenca coloro che sono deceduti durante l'intervallo.
La quarta colonna indica il numero di persone che mancano ai follow-up e la quinta colonna mostra il numero di persone che si sono ritirate vive durante l'intervallo.
La sesta colonna presenta il numero effettivo di partecipanti esposti al rischio oggetto di studio.
Il conteggio è considerato efficace perché si adatta ai partecipanti che sono stati ritirati vivi o persi al follow-up, supponendo che i ritiri avvengano in modo uniforme durante l'intervallo.
In genere si stima che i prelievi avvengano a metà dell'intervallo, portando a una riduzione della metà del denominatore per il calcolo dei rischi.
Le due colonne seguenti sono probabilità condizionali di morte e sopravvivenza. In genere vengono calcolati come segue.
Infine, l'ultima colonna misura i tassi di sopravvivenza cumulativa in tutti gli intervalli.

la tavola di mortalità

Una tavola di mortalità, o tavola di sopravvivenza, è uno strumento statistico che riassume i modelli di mortalità e sopravvivenza di una popolazione, fornendo informazioni dettagliate sulla probabilità di sopravvivenza o di morte in diversi intervalli di età all'interno di una coorte. Organizzando i dati sulle probabilità di sopravvivenza e sui tassi di mortalità, le tavole di sopravvivenza offrono un'istantanea chiara delle dinamiche della popolazione nel tempo. Sono ampiamente utilizzate in demografia, sanità pubblica, scienze attuariali ed ecologia per analizzare l'aspettativa di vita, progettare interventi sanitari, stimare i rischi assicurativi e studiare i modelli di sopravvivenza delle specie in vari ecosistemi. In generale, una tipica tavola di sopravvivenza è suddivisa in diverse colonne chiave:

<ol>
	<li>Intervallo di età: rappresenta intervalli di età specifici. Questa colonna suddivide la popolazione in intervalli distinti, come 0-5 anni, 5-10 anni, ecc.</li>
	<li>Numero di vivi: indica il numero di individui sopravvissuti all'inizio di ogni intervallo di età. Partendo da una coorte ipotetica (spesso 100.000), questa colonna mostra quanti sono ancora vivi a ogni intervallo di età.</li>
	<li>Numero di decessi: mostra il numero di individui che muoiono in ogni intervallo. Viene calcolato sottraendo il numero di persone in vita alla fine di un intervallo dal numero di persone in vita all'inizio.</li>
	<li>Tasso di mortalità: rappresenta la probabilità di morire durante l'intervallo di età per coloro che erano in vita all'inizio dell'intervallo. Fornisce una probabilità di morte specifica per età.</li>
	<li>Probabilità di sopravvivenza: rappresenta la probabilità di sopravvivere all'intervallo di età. È il complemento del tasso di mortalità.</li>
	<li>Aspettativa di vita: indica la media degli anni rimanenti che un individuo di età (x) dovrebbe vivere. Viene calcolato sommando gli anni-persona vissuti da coloro che erano in vita in ogni fascia di età successiva e dividendo per il numero di persone in vita all'età (x).</li>
</ol>

Le tavole di mortalità possono essere categorizzate in tavole di mortalità di coorte, che tracciano un gruppo di individui nati nello stesso periodo nel corso della loro vita, e tavole di mortalità di periodo, che offrono un'istantanea dei tassi di mortalità per una popolazione in un momento specifico. Queste tavole sono preziose per comprendere la salute della popolazione, prevedere la durata della vita futura, calcolare i premi delle assicurazioni sulla vita e confrontare i modelli di sopravvivenza tra popolazioni o gruppi. Ad esempio, possono evidenziare le differenze nell'aspettativa di vita tra diversi paesi o valutare l'impatto di specifici interventi sui tassi di sopravvivenza.

La Tavola di Mortalità

Una tavola di vita o una tavola di mortalità rappresenta i modelli di sopravvivenza di una popolazione.
Comprende più colonne, ognuna delle quali ha uno scopo pratico, ...

Education

Didattica

JoVE Core

Statistics

Statistica

Unit 1

Unità 1

Survival Analysis

Analisi della sopravvivenza

KEY TERMS AND CONCEPTS

TERMINI E CONCETTI CHIAVE

life tables and survival patterns

A life table is a statistical tool that shows mortality and survival patterns in a population. It organizes data across age intervals so students can see how likely a group is to survive or die at each stage of life. The table gives a clear snapshot of population dynamics over time.

Life tables are used in demography, public health, actuarial science, and ecology. They help scientists study life expectancy, plan health interventions, estimate insurance risk, and compare how species survive in different ecosystems. They are also useful for comparing survival patterns across populations or groups, such as differences in life expectancy between countries.

A typical life table includes several important columns. Age interval lists the age range being measured, such as 0-5 years or 5-10 years. Number alive shows how many individuals are still alive at the start of each interval, often beginning with a hypothetical cohort of 100,000.

Other columns describe changes within each age range. Number of deaths shows how many individuals die during the interval. Mortality rate gives the probability of dying during that age period, and survival probability shows the chance of surviving it. Life expectancy tells the average number of years an individual of age x is expected to live, based on the person-years lived by those who remain alive in later age groups.

Life tables are commonly grouped into cohort life tables and period life tables. A cohort life table tracks a group of individuals born during the same period over their lifetimes. A period life table gives a snapshot of mortality rates for a population at a specific point in time. Together, these tables help researchers forecast future lifespans and assess the effect of specific interventions on survival rates.

Life Tables and Survival Patterns

introduction to survival analysis

Time-to-Event Data and Censoring

Survival analysis is a statistical method for time-to-event data. The event can be death, disease relapse, system failure, or recovery. It helps estimate survival time, which is the time until a specific event occurs, and it also shows what factors may affect that time. A key idea in survival analysis is censoring. Censoring happens when the event of interest has not been observed for some people during the study period. Because the data are incomplete in those cases, survival analysis uses...

life tables

A life table is a statistical tool that shows mortality and survival patterns in a population. It organizes data across age intervals so students can see how likely a group is to survive or die at each stage of life. The table gives a clear snapshot of population dynamics over time. Life tables are used in demography, public health, actuarial science, and ecology. They help scientists study life expectancy, plan health interventions, estimate insurance risk, and compare how species survive in...

survival curves

Kaplan-Meier Survival Curve Basics

Kaplan-Meier survival curves show how the chance of staying event-free changes over time. They are used to track survival in a population and to compare groups in medicine, public health, and reliability engineering. The Kaplan-Meier estimator is the most common way to build these curves. It is a non-parametric method, which means it does not assume a fixed pattern for the data. The result is a stepwise line that drops each time an event happens, such as death, disease recurrence, or...

actuarial approach

Life Table Method for Survival Rates

The life table method, also called the actuarial approach, is used to estimate survival rates in clinical and population studies. It began in life insurance, where risk over time must be measured carefully. In health research, it gives a clearer picture of survival when some participants are lost to follow-up or die from causes unrelated to the study. This method works by dividing the study period into set intervals, usually one year. That makes it useful for tracking outcomes over time,...

kaplan-meier approach

Survival Curves with Kaplan-Meier Data

The Kaplan-Meier estimator is a non-parametric method for estimating a survival function from time-to-event data. It is commonly used in medical research to track how many patients survive for a set time after treatment. It is also important in clinical trials, epidemiological studies, and reliability engineering. This method helps researchers study survival probabilities over time, even when some data are incomplete. That incomplete data is called censored data, which means the exact event...

assumptions of survival analysis

Survival Analysis Assumptions in Studies

Survival analysis studies the time until an event happens. The event may be death in a living organism or failure in a mechanical system. These models are used in medicine, biology, engineering, and public health to study time-to-event data. Careful study design matters because the method depends on several key assumptions. One common feature of survival times is positive skewness. This means events often happen early, while fewer cases occur later. Survival data also often include censoring,...

comparing the survival analysis of two or more groups

comparing-the-survival-analysis-of-two-or-more-groups

Kaplan-Meier Curves and Hazard Ratios

Kaplan-Meier curves and hazard ratios help researchers compare survival time between groups. Survival analysis looks at the time until an event happens, such as death, disease recurrence, or recovery. It is a key tool in medical research. A major strength of survival analysis is that it can handle censored data. Censored data means the event has not happened for some participants by the end of the study, or it has not been observed. This makes survival analysis different from standard...

the mantel-cox log-rank test

Log-Rank Test for Comparing Survival Curves

The Mantel-Cox log-rank test compares survival curves from two groups. It checks whether the groups have a statistically significant difference in survival time. This makes it useful when the timing of an event matters, such as death or disease recurrence. The log-rank test is non-parametric. That means it does not assume a specific distribution for the survival data. It is also useful in medical research, where it often helps compare a new treatment with a control or standard treatment in...

applications of life tables

Life Tables in Public Policy and Science

Life tables are used in many fields to study mortality and survival rates. They give a numerical way to examine how long people or living things are likely to survive. This makes them useful for public health, business planning, and scientific research. In demography and public health, life tables help experts study population changes and predict future trends. They can show patterns such as an aging population or the effect of a health policy. In Nigeria, health officials used survival rates...

cancer survival analysis

Cancer Survival Curves and Risk Factors

Cancer survival analysis measures how long it takes from diagnosis or the start of treatment to a specific outcome, such as remission or death. It helps researchers judge treatment effectiveness and understand what affects patient outcomes. These results also support clinical decisions and prognostic evaluations. Survival data are often skewed and not normally distributed. They also include censored cases, where the full survival time is unknown because the study ends, a patient is lost to...

hazard rate

Modeling Event Risk Over Time

Hazard rate is a statistical measure that describes how event risk changes over time. It is also called the hazard function or failure rate. In survival analysis, it shows the instantaneous rate at which an event occurs, but only after the subject has not had the event yet. From a probability view, hazard rate gives the chance that a subject will have the event in a very small time interval. That chance is conditional on surviving to the start of that interval. From a frequency view, it can...

hazard ratio

Hazard Ratio in Clinical Trials

The hazard ratio is a way to compare event risk in clinical trials. It is often used to study events such as death or disease recurrence in two groups over time. The two groups are usually a treatment group and a control group. A hazard ratio compares hazard rates, which are the instantaneous risk of an event happening at a given moment. It shows how the risk in one group relates to the risk in the other group. In a cancer drug study, for example, the hazard ratio can show how a new treatment...

truncation in survival analysis

Left and Right Truncation in Survival Data

Truncation in survival analysis describes data loss caused by the timing of an event or by when a subject can enter a study. It can happen in two forms: left truncation and right truncation. In both cases, some individuals are left out of the dataset before analysis begins. Left truncation happens when people who had the event before a set time are not included in the study. This often occurs with delayed entry, which means a person is only observed if they survive until the entry point. For...

censoring survival data

Types of Censoring in Survival Analysis

Survival analysis studies time-to-event data, which tracks how long it takes for an outcome to happen. It is used in medicine, engineering, and social science. A common problem in this type of data is censoring, which means the full event time is not observed for every person or item. Censoring can happen for several reasons and in different patterns. The most common kind is right censoring. This happens when the event has not occurred by the end of the study or when a participant is lost to...

survival tree

Survival Tree in Time-to-Event Analysis

A survival tree is a non-parametric tool in survival analysis that links predictor variables, or covariates, to survival time. Survival time is the time until an event of interest occurs. It is useful when some data are censored, which means the event has not happened for some people by the end of the study or the exact event time is unknown. Building a survival tree starts with a dataset that includes covariates, survival time, and a censoring indicator for each subject. The data must be...

parametric survival analysis: weibull and exponential methods

parametric-survival-analysis-weibull-and-exponential-methods

Modeling Survival Time with Weibull and Exponential

Parametric survival analysis models survival time by assuming a specific probability distribution for when an event occurs. The Weibull and exponential distributions are two common choices because they are flexible and relatively straightforward to use. The Weibull distribution is a flexible model in parametric survival analysis. It can describe both increasing and decreasing hazard rates, depending on its shape parameter beta. When beta is greater than 1, the hazard rate rises over time. That...

key terms and concepts

Explore life tables as tools for tracking survival, mortality rates, and life expectancy across age intervals in populations, public health, and ecology.

Life Tables and Survival Patterns | JoVE K12

statistics

JoVE Core Statistica introduce agli studenti i concetti e i metodi di raccolta, analisi, presentazione e interpretazione dei dati. Queste video lezioni animate forniscono una comprensione della statistica che è di beneficio agli studenti di molte discipline. Inoltre, i video degli "Scienziati in azione" mostrano l'applicazione dei concetti teorici in esperimenti di ricerca tradizionali e innovativi eseguiti in laboratori internazionali.

Chemistry and Physics

IPC.1

IPC.1.F

Observational Research

Source: Laboratories of Gary Lewandowski, Dave Strohmetz, and Natalie Ciarocco&#8212;Monmouth University

If you want to know how someone thinks or feels, ...

Solving Problems in Physics

Problem-solving is the ability to apply general physical principles to specific situations, usually expressed by equations. It is an essential skill in ...

how-children-solve-problems-using-causal-reasoning

How Children Solve Problems Using Causal Reasoning

Source: Laboratories of Judith Danovitch and Nicholaus Noles&#8212;University of Louisville
Imagine a young child hears an adult say, &#8220;I want to ...

Naturalistic Observations

If you want to understand how behavior occurs, one of the best ways to gain information is to simply observe the behavior in its natural context. However, ...

Models, Theories, and Laws

Scientists frequently use models to help them comprehend a specific collection of phenomena. In physics, a model is a condensed version of a physical ...

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The Scientific Method

The scientific method is a detailed, empirical problem-solving process used by biologists and other scientists. This iterative approach involves ...

Observational Learning

Observational learning, also known as imitation or modeling, occurs when an individual observes and replicates another&#39;s behavior.
The Bobo doll ...

Perspectives on Cognitive Psychology

Source: Laboratory of Jonathan Flombaum&#8212;Johns Hopkins University

As an Assistant Professor of Psychology and Cognitive Science at Johns Hopkins ...

Case Studies

There are many research methods available to psychologists in their efforts to understand, describe, and explain behavior and the cognitive and biological ...

Ask questions and define problems based on observations or information from text, phenomena, models, or investigations

PHYS.1.A

Study Design in Statistics

A study design is a set of techniques that allow a researcher to collect and analyze data from different variables defined for a specific research ...

Experimental Designs

An experimental design is a systematic process that allows researchers to evaluate the relationship between dependent and independent variables. There are ...

Realism in Experimentation

Source: Laboratories of Gary Lewandowski, Dave Strohmetz, and Natalie Ciarocco&#8212;Monmouth University

In an ideal world researchers would conduct ...

Data Collection by Experiments

Data collection is a systematic method of obtaining, observing, measuring, and analyzing accurate information. An experimental study is a standard method ...

Scientific Method

Observation and Background Research
ExpandNOTE: The first two steps in the scientific process involve studying and observing natural phenomena of ...

The Scientific Method in Nursing Process

The scientific method provides the foundation for any research. It is the most reliable and objective of all forms of gaining knowledge and guides in ...

Observational Studies

Observational studies are a type of analytical study where researchers observe events without any interventions. In other words, the researcher does not ...

Study Designs in Epidemiology

Consider an example of testing calcium&#39;s effect on a woman&#39;s bone weight.
In an ideal study design, the same woman would be observed in two ...

What is an Experiment?

An experiment is a planned activity carried out under controlled conditions. The purpose of an experiment is to investigate the relationship between two ...

Categories and Inductive Inferences

Source: Laboratories of Nicholaus Noles and Judith Danovitch&#8212;University of Louisville
It might be possible for the human brain to keep track of each ...

from-theory-to-design-the-role-of-creativity-in-designing-experiments

From Theory to Design: The Role of Creativity in Designing Experiments

Source: Laboratories of Gary Lewandowski, Dave Strohmetz, and Natalie Ciarocco&#8212;Monmouth University

Research studies come into being when a ...

Apply scientific practices to plan and conduct descriptive, comparative, and experimental investigations, and use engineering practices to design solutions to problems

PHYS.1.B

guidelines-in-case-of-a-laboratory-emergency

Guidelines in Case of a Laboratory Emergency

Robert M. Rioux &amp; Zhifeng Chen, Pennsylvania State University, University Park, PA
The most common laboratory emergencies include chemical spills, ...

electrical-safety-precautions-and-basic-equipment

Electrical Safety Precautions and Basic Equipment

Source: Ali Bazzi, Department of Electrical Engineering, University of Connecticut, Storrs, CT.
Electric machines and power electronics experiments ...

Electrical Safety

Robert M. Rioux &amp; Suprita Jharimune, Pennsylvania State University, University Park, PA
Among the many hazards present in the laboratory, electrical ...

Emergency Eyewash and Shower Stations

Robert M. Rioux, Pennsylvania State University, University Park, PA
The Occupational Safety and Health Administration (OSHA) mandates that an emergency ...

Use appropriate safety equipment and practices during laboratory, classroom, and field investigations as outlined in Texas Education Agency-approved safety standards

PHYS.1.C

Common Lab Glassware and Uses

Source: Laboratory of Dr. Neal Abrams &#8212; SUNY College of Environmental Science and Forestry
Glassware is a regular appearance in the professional ...

Lab Techniques

Source: Smaa Koraym at Johns Hopkins University, MD, USA

	Determining the Density of an EggExpand
	Density is a measure of how compact a substance or ...

Scientific Measurement and Lab Skills

Source: Smaa Koraym at Johns Hopkins University, MD, USA

	Measuring Diameter and CircumferenceExpand
	Error can be introduced in any experiment, even ...

Cleaning Glassware

Source: Vy M. Dong and Daniel Kim, Department of Chemistry, University of California, Irvine, CA
Organic synthesis is about transforming a readily ...

Proper Lab Notebook Keeping

Source: Lara Al Hariri and Ahmed Basabrain at the University of Massachusetts Amherst, MA, USA

	Nitration of Methyl BenzoateExpand
	From this lab onward, ...

sample-preparation-for-analytical-characterization

Sample Preparation for Analytical Characterization

Source: Laboratory of Dr. B. Jill Venton - University of Virginia
Sample preparation is the way in which&#160;a sample is treated to prepare&#160;for ...

Making Solutions in the Laboratory

The ability to successfully make solutions is a basic laboratory skill performed in virtually all biological and chemical experiments.  A solution is a ...

Use appropriate tools such as balances, ballistic carts or equivalent, batteries, computers, constant velocity cars, convex lenses, copper wire, discharge tubes with power supply (H, He, Ne, Ar), data acquisition probes and software, dynamics and force demonstration equipment, electrostatic generators, electrostatic kits, friction blocks, graph paper, graphing technology, hand-held visual spectroscopes, inclined planes, iron filings, lab masses, laser pointers, magnets, magnetic compasses, metric rulers, motion detectors, multimeters (current, voltage, resistance), optics bench, optics kit, photogates, plane mirrors, prisms, protractors, pulleys, resistors, rope or string, scientific calculators, stopwatches, springs, spring scales, switches, tuning forks, wave generators, or other equipment and materials that will produce the same results.

PHYS.1.D

Units and Standards of Measurement

A physical quantity is defined either by specifying its measurement method or by stating how it is calculated from other measurements. For example, ...

International System of Units

The International System of Units, known as the SI system, is a universally accepted measurement system recognized and used worldwide. The SI system is ...

Base Quantities and Derived Quantities

In any system of units, the units for some physical quantities must be specified through a measurement process. These measurements are the base quantities ...

How Data are Classified: Numerical Data

Data that are countable or measurable in specific units are called numerical or quantitative data. Quantitative data are always numbers. Quantitative data ...

Quantitative Analysis

Quantitative analysis is a technique for measuring the amount of specific constituents in a sample. When the sample&#39;s composition is unknown, ...

Qualitative Analysis

Qualitative analysis is the process of identifying elements, ions, or compounds in an unknown sample. It is the first and most fundamental type of ...

Collect quantitative data using the International System of Units (SI) and qualitative data as evidence

PHYS.1.E

Review and Preview

Data are individual items of information obtained from a population or sample. Data may be classified as qualitative (categorical), quantitative ...

Ogive Graph

An ogive graph is sometimes called a cumulative frequency polygon. It is one type of frequency polygon that shows cumulative frequency. In other words, ...

Histogram

The histogram is a graphical representation in the x-y form of data distribution in a data set. The horizontal x-axis is labeled with what the data ...

Relative Frequency Histogram

The relative frequency depicts the proportion of data points that have each value. The frequency tells the number of data points that have each value. ...

Scatter Plot

The most common and easiest way to display the relationship between two variables, x and y, is a scatter plot. A scatter plot shows the direction of a ...

Time-Series Graph

A time-series graph is a line graph with repeated measurements taken at successive intervals of time. It is also called a time series chart. To construct ...

Bar Graph

A bar graph is also called a bar chart and consists of bars that are separated from each other. It either uses horizontal or vertical bars to show ...

Multiple Bar Graph

As the name suggests, a multiple bar graph is the same as a bar graph but has multiple bars to depict relationships between different data values. One can ...

Pareto Chart

A Pareto chart is a bar graph or a combination of both line and bar graphs. The bar lengths represent the individual values or the frequency, while the ...

Pie Chart

A pie chart (or a pie graph) is a circular graphical chart or a pictorial representation of categorical data. It is divided into slices of pie each ...

A life table or a mortality table represents the survival patterns of a population.
It comprises multiple columns, each serving a practical purpose, ...

Contingency Table

A contingency table provides a way of portraying data that can facilitate calculating probabilities. It is a method of displaying a frequency distribution ...

Organize quantitative and qualitative data using bar charts, line graphs, scatter plots, data tables, labeled diagrams, and conceptual mathematical relationships

Basic Concept

Engineering mechanics is a branch of engineering that studies motion and the forces acting on objects. It is a fundamental subject and forms the basis of ...

Problem Solving in Statics

Problem-solving in statics is a crucial aspect of engineering and physics that involves resolving issues associated with bodies in a state of equilibrium. ...

Develop and use models to represent phenomena, systems, processes, or solutions to engineering problems

IPC.1.G

Scientific and engineering practices. The student, for at least 40% of instructional time, asks questions, identifies problems, and plans and safely conducts classroom, laboratory, and field investigations to answer questions, explain phenomena, or design solutions using appropriate tools and models. The student is expected to:

Life Tables and Survival Patterns

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