Measuring and Describing Disease (2) Flashcards
What is the pyramid structure for the levels of research?
- Systematic reviews and Meta-anaysis
- Randomised Controlled Trials
- Cohort Studies
- Case-control Studies
- Case series, Case Reports
- Editorials, Expert Opinions
What is a DALY?
Disability Adjusted Life Years - measure of disease burden that combines years of life lost from ill-health, disability or premature death
What are the 3 groups of diseases?
- Communicable
- Non-communicable
- Injuries
What is meant by the term mortality?
What is meant by the term morbidity?
Mortality - deaths
Morbidity - illnesses / diseases
Are the same diseases consistent in all age groups?
No, disease is distributed differently between genders and age groups
Is mental health as important as physical health?
Yes, mental health illnesses are common - can also lead to physical health issues e.g. self-harm, substance misuse, etc.
For continuous quantitative data, what type of measures are used?
Summary measures - mean, median, mode
For discrete quantitative data, what type of measures are used?
Measures of frequency - odds, prevalence, cumulative incidence, evidence rate
What is meant by odds?
How are odds of a disease calculated?
Ratio of -
the number of people with the disease : number of people without the disease
No. of people with disease / no. of people without disease
What is meant by prevalence?
How is prevalence calculated? (usually presented as a percentage)
Proportion of individuals in a population who have the disease at a specific time point
no. of people with the disease / total no. of people in the population
Always specify the time point
What are the strengths and weaknesses of prevalence?
Reflects occurrence and duration of a disease
Does not show how many new cases
What is meant by cumulative incidence?
How is cumulative incidence calculated?
usually presented as a percentage
Measures the occurrence of disease in the population - proportion of the population with a new event during a given time period (AKA incidence proportion or risk)
no. of new cases during period of interest / number of disease free individuals at the start of the time period
Must specify time period
What are the strengths and weaknesses of cumulative incidence?
Tells you number of new cases that arise in a time period
Methodology requires follow up / longitudinal - no new ppts can join, and current ppts must stay on
What is meant by person time?
Person time = measures the time ppts spend in the study
e.g. 3 hours between start of time period and contacting the disease = 3-person hours
Person time can be in minutes, hours, days, years etc.
What is meant by incidence rate?
How is incidence rate measured?
Number of new cases per unit of person time
No. of new cases during the follow up period / total person-time by disease free individuals during the same period
