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Estimating Disease Duration in Cross-sectional Surveys.
Wolf-Peter Schmidt1, Sophie Boisson, Michael G Kenward
1From the aFaculty of Infectious and Tropical Diseases, Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom; and bFaculty of Epidemiology and Population Health, Department of Medical Statistics, London School of Hygiene and Tropical Medicine, London, United Kingdom.
Epidemiology (Cambridge, Mass.)
|August 7, 2015
Summary
Estimating average disease episode duration is possible using prevalence data from just two consecutive days. This method simplifies duration calculation in cross-sectional studies for conditions like diarrhea and respiratory infections.
Area of Science:
- Epidemiology
- Biostatistics
Background:
- Episode duration is a key indicator of disease severity in common episodic conditions.
- Estimating mean episode duration typically requires both incidence and prevalence data.
- Prevalence data from two consecutive time points can suffice for duration estimation.
Purpose of the Study:
- To introduce a novel method for estimating mean disease episode duration using prevalence data alone.
- To provide a practical tool for epidemiological research and public health surveillance.
Main Methods:
- Derivation of a maximum likelihood estimator for episode duration.
- Simulation studies to evaluate the estimator's performance.
- Application of the estimator to a real-world dataset.
Main Results:
- A new estimator for mean episode duration was developed, requiring only two consecutive days of prevalence data.
- The estimator is more precise for shorter average episode durations.
- The method can be extended to 3 or 4 consecutive days and assumes non-overlapping episodes with a constant incidence rate.
Conclusions:
- The proposed method enables mean disease episode duration estimation in cross-sectional studies.
- Applicable to large-scale health surveys, particularly in low-income settings for endemic diseases.
- Potential use in calculating infectiousness duration with paired daily test results.
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