Flashcards in The Use of Data Deck (44)
What percentage of patients are passed on from primary care to secondary care?
What is the difference between disease and illness?
Disease = symptoms and signs, biomedical perspective
Illness = ideas, concerns and expectations - experience. patients perspective
What are the factors affecting the uptake of care?
Concept of Lay Referral – “Granny knows best”, helpful?
Sources of info – Peers, family, internet TV, health pages of newspaper or women’s mag, “What should I do? Booklet, SHOW (scottish health on the web) website, Practice leaflet or website
Medical factors - new symptoms, visible symptoms, increasing severity, duration etc
Non medical factors – crisis, peer pressure “wife sent me”, patient beliefs, expectations, social class, economic, psychological, environmental, cultural, ethnic, age, gender, media etc
What are the three main aims of epidaemiology?
Description - to describe the amount and distribution of disease in human populations
Explanation - to make clear the natural history and identify aetiological factors for disease
Disease control - to explain the ways preventative measures, public health practices and therapeutic strategies can be developed, implemented, monitored and evaluated for the purposes of disease control
What is the point in epidemiology?
Helps isolate aetiologies
Provides a scope for prevention
Can allow the identification of high risk or priority groups in society
What is relative risk?
The measure of the strength of an association between a suspected risk factor and the disease under study
Relative risk = (incidence of disease in exposed group)/(incidence of disease in unexposed group)
Incidence of disease is measured as a fraction - the denominator is a smaller fraction than the denominator
How is a fundamental measure taken?
What are the sources of epidemiological data?
Hospital activity statistics
Reproductive health statistics
General practice morbidity
Health and household surveys
Social security statistics
Drug misuse databases
Expenditure data from NHS
What is health literacy?
Health literacy is about people having the knowledge, skills, understanding and confidence to use health information, to be active partners in their care, and to navigate health and social care systems.
How is the Scottish government attempted to improve health literacy?
Published 'making it easy'
A health literacy action plan for Scotland
What does SIGN stand for?
Scottish Intercollegiate Guidelines Network.
What is the point of the SIGN guidance?
Aims to aid the transition of new knowledge into action
Helps health and social care professionals and patients to understand medical evidence and use it to make decisions about healthcare
Reduces unwarranted variations in practice and makes sure patients get the best care possible, no matter where they live
Improves healthcare across Scotland by focussing on patient - important outcomes
SIGN is also involved in assessing the quality of evidence
What is a descriptive study?
Attempts to describe the amount and distribution of a disease in a given population
Doesn't give conclusions about causation, might give clues about risk factors and candidate aetiologies
What are the benefits of descriptive studies?
Cheap, quick, valuable initial overview of a problem
What are descriptive studies useful for?
Identifying emerging public health problems through monitoring and surveillance of disease patterns.
Signalling the presence of effects worthy of further investigation.
Assessing the effectiveness of measures of prevention and control (eg, screening programmes).
Assessing needs for health services and service planning.
Generating hypotheses about disease aetiology.
What is a cross sectional study?
It is a measure of disease frequency , survey, prevalence study) - used to make an observation at a single point in time
What conclusions are drawn from cross sectional studies?
Conclusions are drawn about the relationship between diseases and other variables in a defined population
What is a strength and a limitation of cross sectional studies?
Strength - can provide results quickly
Limitation - usually impossible to infer causation
What is a case controlled study?
Two groups of people are compared - those who have the disease of interest (cases) and those who do not (controls)
How are conclusions drawn from case controlled studies?
The two groups have their exposure to a suspected aetiological factor measured. The average exposure between the two groups is compared to identify significant differences - giving clues as to what factors elevate or reduce the risk of the disease under investigation
What are the results in a case controlled study expressed as?
They are expressed as odds ratios or relative risks
Often have a P value associated - indicates how likely to results could just be a chance finding
Cohort studies and randomised trials also express results this way
What is a cohort study?
Baseline data on exposure are collected from a group of people who do not have the disease under study
The group is then followed until a sufficient number have developed the disease to allow analysis
What are trials?
Experiments to test ideas about aetiology or to evaluate interventions
What is the definitive method of assessing any new treatment in medicine?
Randomised control trial
How is a trial assessing aetiology conducted?
Two groups at risk of developing a disease are assembled.
An alteration is made to the intervention group (eg, a suspected causative factor is removed), whilst no alteration is made to the control group. Data on subsequent outcomes (eg, disease incidence) are collected in the same way from both groups, and the relative risk is calculated.
How is a trial assessing new treatment conducted?
the intervention group receive the new therapy, the control group receive the current standard therapy (or a placebo) and the treatment outcomes (eg, reduction in symptoms) are compared in the two groups.
What is meant by standardisation?
A set of techniques used to remove (or adjust for) the effects of differences in age or other confounding variables, when comparing two or more populations
Another variable could be sex
What is the standard mortality ratio?
This is a special kind of standardisation which you may encounter in your reading. It is simply a standardised death rate converted into a ratio for easy comparison. The figure for a standard reference population (eg, Scotland) is taken to be 100 and the standardised death rates for the comparison (study) populations (eg, Grampian) are expressed as a proportion of 100. A figure below one hundred means fewer than expected deaths, and above 100 means more. For example, an SMR of 120 means that 20% more deaths occurred than expected in the study population, allowing for differences in the age and sex structure of the standard and study populations and an SMR of 83 means 17% fewer deaths occurred.
What are the factors to consider when interpreting results?
Standard mortality ratio
Quality of data
Coding and classification