100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Previously searched by you
Previously searched by you
logo
Samenvatting GZW3024 Alle seminars (1-27)! $6.48
Add to cart
Quickly navigate to
Preview
  2.  
  3. Maastricht University (UM)
  4.  
  5. GZW3024 (GZW3024)

Summary

Samenvatting GZW3024 Alle seminars (1-27)!

12 reviews
 43 purchases
  • Course
  • GZW3024 (GZW3024)
  • Institution
  • Maastricht University (UM)

Alle seminars van blok GZW3024 uitgewerkt. Dit document bevat zowel alle vragen, uitleg en SPSS-output die bij de seminars horen (daarom heeft dit bestand ook zo veel pagina's), als een complete uitwerking (inclusief uitleg) van alle vragen. Nederlands/Engels. Nieuw curriculum.

Preview 4 out of 177  pages

Document information

  • April 9, 2018
  • 177
  • 2017/2018
  • Summary

Subjects

  • gzw3024
  • universiteit maastricht
  • statistiek
  • seminars
  • health sciences
  • gezondheidswetenschappen
  • maastricht university
  • voortgezette statistiek en methoden van onderzoek
  • advanced statistics and research me

Written for

  • Maastricht University (UM)
  • Gezondheidswetenschappen
  • GZW3024 (GZW3024)
All documents for this subject (5)

12  reviews

review-writer-avatar

By: maaroub • 3 year ago

review-writer-avatar

By: abcdgw • 4 year ago

review-writer-avatar

By: woutervansantbrink • 3 year ago

review-writer-avatar

By: irisverhoeven • 5 year ago

review-writer-avatar

By: franceswalta • 5 year ago

review-writer-avatar

By: niekebrull • 5 year ago

review-writer-avatar

By: caitlingranosz • 5 year ago

Show more reviews  

Seller

avatar-seller
k_vdh

Reviews received

Content preview

GZW3024: Seminars (1-27)
Seminar 1: Measures of disease frequency and study design
Assignment 1
Researchers can quantify the occurrence of disease by making use of measures of
disease frequency (MODF), such as
 Prevalence (and variants of this MODF: point, period, and lifetime prevalence);
 Incidence (and variants of this MODF: cumulative incidence and incidence
density);
 Mortality;
 Case fatality rate (CFR)

1a. Define all these MODF. How should one calculate these measures?
Prevalence = the number of existing disease cases in the population.

- Point prevalence: part of the population that is diseases at a certain point in time.

(number of disease cases
population )
x 100 %


- Period prevalence: part of the population that had the disease in a certain period
of time. Use the mid-term population.


( )
number of disease cases within a period
x 100 %
( N start + N end )
2

- Life-time prevalence: part of the population that had the disease during their
lifetime.

Incidence = new cases of the disease in the population.

- Cumulative incidence (CI)  closed population.
CI = (Number ofnew cases∈ period P
Total number poplation ❑' a t ris k ' at T 0 )
x 100 %


- Incidence density rate (ID)  open/dynamic and closed population.
ID=
(
number of new cases∈ period P
persons x time ❑' a t ris k ' (' person tim e ' ) )
Mortality rate = total numbers of death within a period of time. De ‘incidence of death’,
calculating the prevalence of death isn’t really possible.

number of deaths
Mortality rate= x 1000
population ❑' a t risk '




1

, Case fatality rate (CFR) = the number of deaths from a specified disease within a certain
period of time. The part of all the people with that disease that died.

CFR=t h e number of deat h s duo ¿ thedisease ¿ x 100 %
t h e number of individuals diagnosed wit h t h e disease

1b. In which of the following designs can these MODF be calculated?
 Case series;
 Ecological study;
 Crossectional study/survey;
 Case-control study;
 Prospective cohort study;
 Retrospective (or ‘historic’) cohort study’
 Randomized controlled trial (RCT)

Indicate in the table below (‘yes’/’no’) whether the specific MODF can be calculated in
the listed study designs:


Prevalence Incidence
Mortality CFR
Lifetime
Point- Period- CI ID
-

Case series No No No No No No Yes

Ecological
Yes Yes Yes Yes Yes Yes Yes
study

Crosssectional
Yes Yes Yes No No No No
study

Case-control
No No No No No No No
study

Prospective
Yes Yes Yes Yes Yes Yes Yes
cohort

Retrospective
Yes Yes Yes Yes Yes Yes Yes
cohort

RCT Yes Yes Yes Yes Yes Yes Yes




Assignment 2
2

,The following table represents the results from a follow-up study over a period of 12
months. In this study the participants are continuously monitored for disease D during
their follow-up. It is assumed that all participants are at-risk as long as they are present
in the study population (indicated in yellow), except when they have the disease
(indicated in blue).




2a. What type of population -‘open’ (or dynamic) or ‘closed’ (or cohort)- is under study?
(Justify your answer.)
This is an open/dynamic population, because not all participants are always present in
the study population and they don’t all enter the population at the start of the study.

2b. What are the sex-specific point prevalences of disease D on the second day of the 6th
month? (Males are ID-numbers A1-A24, females are ID-numbers B1-B26)
Point prevalence males = (2/17) x 100% = 11,8%
Point prevalence females = (2/24) x 100% = 8,3%


3

, 2c. Calculate the point prevalence of disease D for the total population on the second day
of the 6th month.
Point prevalence total population = (4/41) x 100% = 9,8%

2d. Suppose that people could not be cured from disease D. What would then have been
the point prevalence of disease D on the second day of the 6th month?
Point prevalence = (7/41) x 100% = 17,1%

What are now the sex-specific point prevalences of disease D on the second day of the
6th month?
Point prevalence male = (4/17) x 100% = 23,5%
Point prevalence female = (3/24) x 100% = 12,5%

2e. Calculate the incidence of disease D in the total population.
Because it’s an open population, you have to calculate the incidence density.

ID total population = (8+7) / (178 + 187) = = 0,0410
- Total time that people are in the population is 365 months; count the number of
months that every participant is part of the population.
- If someone gets sick two times, he counts as two cases.

2f. Are males or females more likely to develop disease D? (Males are ID-numbers A1-
A24, females are ID-numbers B1-B26)
- Males: (8/178) = 0,0449
- Females: (7/187) = 0,0374
So, males are more likely to develop the disease.

2g. Suppose that due to improvements in the treatment of disease D, the disease
duration is reduced to 50%. What happens to incidences calculated in 2e and 2f?
The incidence density will be reduced, because you have more months ‘at risk’ (person
time) and less months sick. The number of new cases stays the same.

Assignment 3
The following table shows a series of cumulative incidences of disease D (per 100,000
per year) by age and calendar time in a follow-up study in which birth cohorts (i.e.
individuals that were born in the same year(s), born in the same age group) are
measured multiple times.




4

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller k_vdh. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for $6.48. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

68175 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy study notes for 15 years now

Start selling
$6.48  43x  sold
  • (12)
Add to cart
Added