Name: life table method for survival rates
Uploaded: 2025-01-09T15:14:16.000Z
Duration: 1 min 20 s
Channel: JoVE

L’analyse de survie évalue le temps écoulé jusqu’à ce qu’un événement tel qu’un décès ou un échec du traitement se produise. L’approche actuarielle ou table de mortalité, adaptée de l’actuariat, analyse les données de survie.
Dans un scénario d’étude clinique, les participants sont divisés en groupes avec des durées de suivi différentes pour se concentrer sur les périodes critiques, comme la première année après une chirurgie à haut risque.
La méthode actuarielle calcule les taux de survie à des intervalles prédéterminés, en utilisant pleinement les données de tous les participants, y compris ceux qui n’ont pas fait l’objet d’un suivi ou qui sont décédés d’autres causes.
Pour comprendre l’impact sur la survie de la première année, les taux de survie à un an sont calculés en soustrayant le nombre de décès du nombre total de participants et en divisant par le nombre initial.
Seul le sous-ensemble de patients observés pendant les deux années complètes est pris en compte pour estimer la survie à deux ans, en se concentrant sur ceux qui ont survécu la première année et ont continué à survivre la deuxième année.
Cette méthode est cohérente, aide à identifier les tendances à long terme et évalue l’efficacité des traitements ou des interventions, fournissant ainsi un outil solide pour comprendre les résultats de la recherche médicale.

approche actuarielle

Actuarial Approach

L'approche actuarielle, une méthode statistique initialement développée pour l'évaluation des risques d'assurance-vie, est largement utilisée pour calculer les taux de survie dans les études cliniques et de population. Cette méthode tient compte des participants perdus de vue ou de ceux qui décèdent de causes non liées à l'étude, ce qui garantit une représentation plus précise des probabilités de survie

Prenons l'exemple d'une intervention chirurgicale à haut risque avec une mortalité précoce importante. Une étude clinique de deux ans est menée, axée sur la première année critique. Les participants sont divisés en deux groupes : l'un suivi pendant un an et l'autre pendant deux ans. Les taux de survie sont estimés à l'aide de la méthode actuarielle (ou table de survie), qui divise la période d'étude en intervalles, généralement d'un an.

À titre d'illustration, supposons que le premier groupe commence avec 1 000 patients, dont 240 décèdent au cours de la première année. Le deuxième groupe commence également avec 1 000 patients, avec 200 décès au cours de la première année et 16 au cours de la deuxième année. Le taux de survie à un an est calculé en soustrayant le nombre total de décès de la taille de la cohorte initiale et en divisant le résultat par la population de départ:

Taux de survie à un an = (2000 - 240 - 200)/2000 = 0,78 ou 78 %

Cette approche peut également être appliquée aux études sur les résultats à long terme, comme l’évaluation de l’efficacité d’un traitement contre le cancer au fil des ans. La méthode actuarielle tient compte des patients perdus de vue ou décédés de causes non liées, ce qui permet une analyse robuste des effets à long terme.

Pour les taux de survie à deux ans, le calcul devient plus nuancé. Il utilise une probabilité conditionnelle, en prenant en compte uniquement les individus observés pendant les deux années complètes et qui ont survécu à la première année. Le taux de survie à deux ans ne doit pas dépasser le taux à un an et est déterminé en multipliant la probabilité de survivre la première année par la probabilité de survivre la deuxième année, à condition de survivre la première année

Taux de survie à deux ans = 0,78 × 0,98 = 0,7644 ou 76,44 %

Cette méthode sophistiquée, bien que puissante, est confrontée à des défis tels que des données de suivi incomplètes et un enregistrement précis des décès. Malgré ces limites, elle reste particulièrement efficace dans les études de population à grande échelle où le suivi des participants individuels est peu pratique. En tenant compte de la censure et des probabilités de survie basées sur des intervalles, l'approche actuarielle fournit un cadre fiable pour l'analyse de la survie dans divers contextes de recherche.

Approche actuarielle

L’analyse de survie évalue le temps écoulé jusqu’à ce qu’un événement tel qu’un décès ou un échec du traitement se produise. L’approche actuarielle ou table de mortalité, adaptée de l’approche actuarielle ...

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Unit 1

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Survival Analysis

Analyse de survie

KEY TERMS AND CONCEPTS

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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, especially in studies with early deaths after a high-risk surgical procedure. In one example, a two-year study follows two groups. One group is observed for one year, and the other is observed for two years.

The one-year survival rate is found from the starting group size and the number of deaths during that year. In the example, 1,000 patients begin in each group. The first group has 240 deaths in the first year, and the second group has 200 deaths in the first year. Using the actuarial calculation, the one-year survival rate is 78%.

The same method can also be used for long-term studies, such as testing how well a cancer treatment works over several years. It accounts for patients who are not followed for the full study or who die from unrelated causes. That makes the survival estimate more realistic when individual tracking is difficult.

Two-year survival uses conditional probability, which means the second year is calculated only for people who survived the first year and were observed for the full two years. In the example, the second-year survival probability is multiplied by the first-year survival probability. The result is 0.78 times 0.98, or 76.44%.

A two-year survival rate should not be higher than the one-year rate. The method is powerful, but it depends on complete follow-up and accurate death records. Even with those limits, it is especially useful in large population studies where following each person closely is not practical.

Life Table Method for Survival Rates

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actuarial approach

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,...

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key terms and concepts

Learn how the life table method, or actuarial approach, estimates one-year and two-year survival rates while accounting for follow-up losses and unrelated deaths.

Life Table Method for Survival Rates | JoVE K12

statistics

JoVE Core Statistiques introduit aux étudiants les concepts suivants et leurs applications: la collection, l'analyse, la présentation, et l' interprétation des données. En parallèle, les scientifiques à l'action démontrent l’application de ces concepts dans des expériences de recherche classiques et originales réalisées dans des laboratoires du monde entier.

Life Table Method for Survival Rates

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