Cours 3

Question 1

Comment calcul t-on le taux de mortalité?

Answer 1

même chose que l’incidence
I = n/T
numérateur: nb de décès
T: cumul des temps d’observation de chaque individu à risque de développer l’issue (décès)
(les effectifs sont mesurés au milieux de l’année)

Question 2

Qu’est-ce que la probabilité de décès?

Answer 2

même chose de l’incidence cumulée
nb de décès pour un temps X sur un nb de personnes à risque
(les effectifs sont mesurés au début de l’année)

Question 3

Qu’est-ce que la létalité?

Answer 3

L = d/m
proportion des personnes atteintes d’une maladie (m) quoi vont mourir(d)

Question 4

Qu’est-ce que la mortalité proportionnelle?

Answer 4

proportion des décès permis tous les gens qui sont décédés selon certains caractéristiques (ex : tranches d’âge, maladie,etc)

*dénominateur par comparable

Question 5

Qu’est-ce que les années potentielles de vie perdue?

Answer 5

personnes mortes d’une même cause
+
(75ans - âge du décès)

Question 6

Pourquoi calcule t-on la mortalité plutôt que l’incidence?

Answer 6

plus facile à obtenir

Question 7

2 façons d’augmenter l’incidence de mortalité

Answer 7

réelle: augmentation des facteurs de risques
apparente: augmentation des capacités de dx des cas

Question 8

Quelle est la problématique avec les données de mortalité?

Answer 8

dépend de la qualité des certificats de décès

Question 9

Qu’est-ce qu’un ajustement direct?

Answer 9

Application des taux spécifiques (à chaque groupe d’âge) à la structure (d’âge) d’une population de référence
Avantages:
comparer 2 populations
bloque le facteur de confusion (souvent âge)
ex: comparer 2 populations qui n’ont pas le même nb d’habitant en mettant le nb d’habitant à 1000 et appliquant les % pour 1000 habitants

Question 10

Qu’est-ce que l’ajustement indirect?

Answer 10

Est utilisé lorsque les taux de décès spécifique de chaque strate ne sont pas connus.
— Utilisation de SMR
Prendre les taux de décès d’une population de référence et l’appliquer à une population spécifique

désavantage: difficile de comparer plusieurs population avec cette méthode

Question 11

Ratio de mortalité standardisé (SMR)

Answer 11

nb décès observé/ nb décès attendu

Question 12

Modification de la tendance (artéfact)

Answer 12

1. Numérateur —
   Erreur Dx
   — Erreur âge
   — Changement de classification
2. Dénominateur
   — Erreur de recensement
   — Erreur de classification par caractéristiques démographique
   — Différence de % de population à risque

Question 13

Modification de la tendance (réelle)

Answer 13

changement incidence
changement survie
changement de la distribution selon âge

Question 14

Pourquoi s’intéresser à la mortalité?

Answer 14

index pour la sévérité d’une maladie

Question 15

1-2. In an Asian country with a population of 6 million people, 60,000 deaths occurred during the year ending
December 31, 2010. These included 30,000 deaths from cholera in 100,000 people who were sick with
cholera.
A) What was the cause-specific mortality rate from cholera in 2010? _____
B) What was the case-fatality from cholera in 2010? _____

Answer 15

5/1000
30%

Question 16

3.Age-adjusted death rates are used to:
a. Correct death rates for errors in the
statement of age
b. Determine the actual number of deaths that occurred in specific age groups in a population
c. Correct death rates for missing age information
d. Compare deaths in persons of the same age group
e. Eliminate the effects of differences in the age distributions of populations in comparing death rates

Answer 16

e

Question 17

4.The mortality rate from disease X in city A is 75/100,000 in persons 65 to 69 years old. The mortality rate from the
same disease in city B is 150/100,000 in persons 65 to 69 years old. The inference that disease X is two times more prevalent in persons 65 to 69 years old in city B than it is in persons 65 to 69 years old in city A is:
a. Correct
b. Incorrect, because of failure to distinguish between prevalence and mortality
c. Incorrect, because of failure to adjust for differences in age distributions
d. Incorrect, because of failure to distinguish between period and point prevalence
e. Incorrect, because a proportion is used when a rate is required to support the inference

Answer 17

b

Question 18

5.The incidence rate of a disease is five times greater in women than in men, but the prevalence rates show no sex difference. The best explanation is that:
a. The crude all-cause mortality rate is greater in women
b. The case-fatality from this disease is greater in women
c. The case-fatality from this disease is lower in women
d. The duration of this disease is shorter in men
e. Risk factors for the disease are more common in women

Answer 18

b

Question 19

6.For a disease such as pancreatic cancer, which is highly fatal and of short duration:
a. Incidence rates and mortality rates will be similar
b. Mortality rates will be much higher than incidence rates
c. Incidence rates will be much higher than mortality rates
d. Incidence rates will be unrelated to mortality rates
e. None of the above

Answer 19

a

Question 20

7.In 1990, there were 4,500 deaths due to lung diseases in miners aged 20 to 64 years. The expected number of deaths in this occupational group, based on age-specific death rates from lung diseases in all males aged 20 to 64 years, was 1,800 during 1990. What was the standardized mortality ratio (SMR) for lung diseases in miners? ______

Answer 20

2.5 or 250

Question 21

QUESTION 8-10-11-12-12 p.92 dans le manuel d’épidémiologie

Answer 21

fais les, juste pour pratiquer
8- d
10-d
11- 9.6/1000
12- e

Question 22

9. A program manager from an international health funding agency needs to identify regions that would benefit from an intervention aimed at reducing premature disability. The program manager asks a health care consultant to develop a proposal using an index that would help her make this decision. Which of the following would best serve this purpose?
   a. Case-fatality
   b. Crude mortality rate
   c. Disability-adjusted life-years
   d. Standardized mortality ratio

Answer 22

c

Question 23

13. Which of the following statements regarding direct adjustment is TRUE?
    a. The age-adjusted mortality rate of
    community X is still higher than the
    mortality rate of community Y, as compared to the crude mortality rate
    b. Age-adjusted mortality rates for community X should be used to make decisions regarding allocation of funding for hospital care of the dying in community X
    c. For direct age-adjustment, the weight for a given age category is the percentage of deaths for that age group
    d. For direct age-adjustment, the weight for a given age category is the number of
    individuals in the standard population for that age group
    e. The difference in the adjusted mortality rates between community X and community Y is always attributable to differences in age composition between the two populations

Answer 23

d

Question 24

14. Surveillance data indicate that the prevalence of chronic liver disease in the United States increased 104% between the years 1990 and 2008. While chronic liver disease occurs in persons of all ages, the highest mortality rate occurs in people 65 years old or older. The United States has proportionately more people 65 years or older than Country
    X. What would happen if crude mortality rates in the United States were age standardized to the population of Country X in order to compare the risk of dying of chronic liver disease in the two populations?
    a. The age-standardized mortality rate for the United States would be less than the crude mortality rate for the United States
    b. The age-standardized mortality rate for the United States would be greater than the crude mortality rate for the United States
    c. The age-standardized mortality rate for the
    United States would be the same as the crude
    mortality rate for the United States
    d. The age-standardized mortality rate for the United States cannot be used for this comparison
    e. The age-standardized mortality rate for the United States would be the same as the proportionate mortality rate

Answer 24

a

Question 25

15. Among workers in a fish processing plant, 30% of all deaths were due to myocardial infarction. Among workers in a
    brewery, 10% of all deaths were due to myocardial infarction. Investigators concluded that workers in the fish pro-
    cessing plant had a greater risk of death due to myocardial infarction than workers in the brewery. This conclusion:
    a. Is correct
    b. May be incorrect because it is based on proportionate mortality
    c. May be incorrect because it assumes the same case fatality for myocardial infarction in both work sites
    d. May be incorrect because consumed fish oil is protective against death due to myocardial infarction
    e. May be incorrect because the prevalence of myocardial infarction in the two groups is not known

Answer 25

b