Methodology &Study Designs part3

TWO CHARACTERISTICS OF CASES
1. REPRESENTATIVENESS:
Ideally, cases are a random sample of all cases of interest in the source population (e.g. from vital data, registry data). More commonly they are a selection of available cases from a medical care facility. (e.g. from hospitals, clinics)
TWO CHARACTERISTICS OF CASES
1. REPRESENTATIVENESS:
Ideally, cases are a random sample of all cases of interest in the source population (e.g. from vital data, registry data). More commonly they are a selection of available cases from a medical care facility. (e.g. from hospitals, clinics)
TWO CHARACTERISTICS OF CASES
1. REPRESENTATIVENESS:
Ideally, cases are a random sample of all cases of interest in the source population (e.g. from vital data, registry data). More commonly they are a selection of available cases from a medical care facility. (e.g. from hospitals, clinics)
2. METHOD OF SELECTION
Selection may be from incident or prevalent cases:
• Incident cases are those derived from ongoing ascertainment of cases over time.
• Prevalent cases are derived from a cross-sectional survey.
2. METHOD OF SELECTION
Selection may be from incident or prevalent cases:
• Incident cases are those derived from ongoing ascertainment of cases over time.
• Prevalent cases are derived from a cross-sectional survey.