Methodological issues of retrospective surveys for measuring mortality of highly clustered diseases: case study of the 2014–16 Ebola outbreak in Bo District, Sierra Leone
Background There is a lack of empirical data on design effects (DEFF) for mortality rate for highly clustered data such as with Ebola virus disease (EVD), along with a lack of documentation of methodological limitations and operational utility of mortality estimated from cluster-sampled studies when...
Saved in:
| Main Authors: | , , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Taylor & Francis Group
2024-12-01
|
| Series: | Global Health Action |
| Subjects: | |
| Online Access: | http://dx.doi.org/10.1080/16549716.2024.2331291 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832096682787995648 |
|---|---|
| author | Grazia Caleo Kamalini Lokuge Katina Kardamanidis Jane Greig Jaroslava Belava Emer Kilbride Alhaji Sayui Turay Gbessay Saffa Ronald Kremer Francesco Grandesso Kostas Danis Armand Sprecher Gian Luca Di Tanna Holly Baker Helen A. Weiss |
| author_facet | Grazia Caleo Kamalini Lokuge Katina Kardamanidis Jane Greig Jaroslava Belava Emer Kilbride Alhaji Sayui Turay Gbessay Saffa Ronald Kremer Francesco Grandesso Kostas Danis Armand Sprecher Gian Luca Di Tanna Holly Baker Helen A. Weiss |
| author_sort | Grazia Caleo |
| collection | DOAJ |
| description | Background There is a lack of empirical data on design effects (DEFF) for mortality rate for highly clustered data such as with Ebola virus disease (EVD), along with a lack of documentation of methodological limitations and operational utility of mortality estimated from cluster-sampled studies when the DEFF is high. Objectives The objectives of this paper are to report EVD mortality rate and DEFF estimates, and discuss the methodological limitations of cluster surveys when data are highly clustered such as during an EVD outbreak. Methods We analysed the outputs of two independent population-based surveys conducted at the end of the 2014–2016 EVD outbreak in Bo District, Sierra Leone, in urban and rural areas. In each area, 35 clusters of 14 households were selected with probability proportional to population size. We collected information on morbidity, mortality and changes in household composition during the recall period (May 2014 to April 2015). Rates were calculated for all-cause, all-age, under-5 and EVD-specific mortality, respectively, by areas and overall. Crude and adjusted mortality rates were estimated using Poisson regression, accounting for the surveys sample weights and the clustered design. Results Overall 980 households and 6,522 individuals participated in both surveys. A total of 64 deaths were reported, of which 20 were attributed to EVD. The crude and EVD-specific mortality rates were 0.35/10,000 person-days (95%CI: 0.23–0.52) and 0.12/10,000 person-days (95%CI: 0.05–0.32), respectively. The DEFF for EVD mortality was 5.53, and for non-EVD mortality, it was 1.53. DEFF for EVD-specific mortality was 6.18 in the rural area and 0.58 in the urban area. DEFF for non-EVD-specific mortality was 1.87 in the rural area and 0.44 in the urban area. Conclusion Our findings demonstrate a high degree of clustering; this contributed to imprecise mortality estimates, which have limited utility when assessing the impact of disease. We provide DEFF estimates that can inform future cluster surveys and discuss design improvements to mitigate the limitations of surveys for highly clustered data. |
| format | Article |
| id | doaj-art-8d1385b31ab447d6a48315bc3356e333 |
| institution | Kabale University |
| issn | 1654-9880 |
| language | English |
| publishDate | 2024-12-01 |
| publisher | Taylor & Francis Group |
| record_format | Article |
| series | Global Health Action |
| spelling | doaj-art-8d1385b31ab447d6a48315bc3356e3332025-02-05T12:46:13ZengTaylor & Francis GroupGlobal Health Action1654-98802024-12-0117110.1080/16549716.2024.23312912331291Methodological issues of retrospective surveys for measuring mortality of highly clustered diseases: case study of the 2014–16 Ebola outbreak in Bo District, Sierra LeoneGrazia Caleo0Kamalini Lokuge1Katina Kardamanidis2Jane Greig3Jaroslava Belava4Emer Kilbride5Alhaji Sayui Turay6Gbessay Saffa7Ronald Kremer8Francesco Grandesso9Kostas Danis10Armand Sprecher11Gian Luca Di Tanna12Holly Baker13Helen A. Weiss14Médecins Sans Frontières (MSF)Australian National UniversityMSFMédecins Sans Frontières (MSF)MSFMSFMinistry of Health and SanitationMinistry of Health and SanitationMSFEpicentreThe French National Public Health Agency (SpFrance)Médecins sans FrontièresUniversity of New South WalesMédecins Sans Frontières (MSF)London School of Hygiene and Tropical MedicineBackground There is a lack of empirical data on design effects (DEFF) for mortality rate for highly clustered data such as with Ebola virus disease (EVD), along with a lack of documentation of methodological limitations and operational utility of mortality estimated from cluster-sampled studies when the DEFF is high. Objectives The objectives of this paper are to report EVD mortality rate and DEFF estimates, and discuss the methodological limitations of cluster surveys when data are highly clustered such as during an EVD outbreak. Methods We analysed the outputs of two independent population-based surveys conducted at the end of the 2014–2016 EVD outbreak in Bo District, Sierra Leone, in urban and rural areas. In each area, 35 clusters of 14 households were selected with probability proportional to population size. We collected information on morbidity, mortality and changes in household composition during the recall period (May 2014 to April 2015). Rates were calculated for all-cause, all-age, under-5 and EVD-specific mortality, respectively, by areas and overall. Crude and adjusted mortality rates were estimated using Poisson regression, accounting for the surveys sample weights and the clustered design. Results Overall 980 households and 6,522 individuals participated in both surveys. A total of 64 deaths were reported, of which 20 were attributed to EVD. The crude and EVD-specific mortality rates were 0.35/10,000 person-days (95%CI: 0.23–0.52) and 0.12/10,000 person-days (95%CI: 0.05–0.32), respectively. The DEFF for EVD mortality was 5.53, and for non-EVD mortality, it was 1.53. DEFF for EVD-specific mortality was 6.18 in the rural area and 0.58 in the urban area. DEFF for non-EVD-specific mortality was 1.87 in the rural area and 0.44 in the urban area. Conclusion Our findings demonstrate a high degree of clustering; this contributed to imprecise mortality estimates, which have limited utility when assessing the impact of disease. We provide DEFF estimates that can inform future cluster surveys and discuss design improvements to mitigate the limitations of surveys for highly clustered data.http://dx.doi.org/10.1080/16549716.2024.2331291ebola virus diseasedesign effectscluster surveysmortalityhighly-clustered data |
| spellingShingle | Grazia Caleo Kamalini Lokuge Katina Kardamanidis Jane Greig Jaroslava Belava Emer Kilbride Alhaji Sayui Turay Gbessay Saffa Ronald Kremer Francesco Grandesso Kostas Danis Armand Sprecher Gian Luca Di Tanna Holly Baker Helen A. Weiss Methodological issues of retrospective surveys for measuring mortality of highly clustered diseases: case study of the 2014–16 Ebola outbreak in Bo District, Sierra Leone Global Health Action ebola virus disease design effects cluster surveys mortality highly-clustered data |
| title | Methodological issues of retrospective surveys for measuring mortality of highly clustered diseases: case study of the 2014–16 Ebola outbreak in Bo District, Sierra Leone |
| title_full | Methodological issues of retrospective surveys for measuring mortality of highly clustered diseases: case study of the 2014–16 Ebola outbreak in Bo District, Sierra Leone |
| title_fullStr | Methodological issues of retrospective surveys for measuring mortality of highly clustered diseases: case study of the 2014–16 Ebola outbreak in Bo District, Sierra Leone |
| title_full_unstemmed | Methodological issues of retrospective surveys for measuring mortality of highly clustered diseases: case study of the 2014–16 Ebola outbreak in Bo District, Sierra Leone |
| title_short | Methodological issues of retrospective surveys for measuring mortality of highly clustered diseases: case study of the 2014–16 Ebola outbreak in Bo District, Sierra Leone |
| title_sort | methodological issues of retrospective surveys for measuring mortality of highly clustered diseases case study of the 2014 16 ebola outbreak in bo district sierra leone |
| topic | ebola virus disease design effects cluster surveys mortality highly-clustered data |
| url | http://dx.doi.org/10.1080/16549716.2024.2331291 |
| work_keys_str_mv | AT graziacaleo methodologicalissuesofretrospectivesurveysformeasuringmortalityofhighlyclustereddiseasescasestudyofthe201416ebolaoutbreakinbodistrictsierraleone AT kamalinilokuge methodologicalissuesofretrospectivesurveysformeasuringmortalityofhighlyclustereddiseasescasestudyofthe201416ebolaoutbreakinbodistrictsierraleone AT katinakardamanidis methodologicalissuesofretrospectivesurveysformeasuringmortalityofhighlyclustereddiseasescasestudyofthe201416ebolaoutbreakinbodistrictsierraleone AT janegreig methodologicalissuesofretrospectivesurveysformeasuringmortalityofhighlyclustereddiseasescasestudyofthe201416ebolaoutbreakinbodistrictsierraleone AT jaroslavabelava methodologicalissuesofretrospectivesurveysformeasuringmortalityofhighlyclustereddiseasescasestudyofthe201416ebolaoutbreakinbodistrictsierraleone AT emerkilbride methodologicalissuesofretrospectivesurveysformeasuringmortalityofhighlyclustereddiseasescasestudyofthe201416ebolaoutbreakinbodistrictsierraleone AT alhajisayuituray methodologicalissuesofretrospectivesurveysformeasuringmortalityofhighlyclustereddiseasescasestudyofthe201416ebolaoutbreakinbodistrictsierraleone AT gbessaysaffa methodologicalissuesofretrospectivesurveysformeasuringmortalityofhighlyclustereddiseasescasestudyofthe201416ebolaoutbreakinbodistrictsierraleone AT ronaldkremer methodologicalissuesofretrospectivesurveysformeasuringmortalityofhighlyclustereddiseasescasestudyofthe201416ebolaoutbreakinbodistrictsierraleone AT francescograndesso methodologicalissuesofretrospectivesurveysformeasuringmortalityofhighlyclustereddiseasescasestudyofthe201416ebolaoutbreakinbodistrictsierraleone AT kostasdanis methodologicalissuesofretrospectivesurveysformeasuringmortalityofhighlyclustereddiseasescasestudyofthe201416ebolaoutbreakinbodistrictsierraleone AT armandsprecher methodologicalissuesofretrospectivesurveysformeasuringmortalityofhighlyclustereddiseasescasestudyofthe201416ebolaoutbreakinbodistrictsierraleone AT gianlucaditanna methodologicalissuesofretrospectivesurveysformeasuringmortalityofhighlyclustereddiseasescasestudyofthe201416ebolaoutbreakinbodistrictsierraleone AT hollybaker methodologicalissuesofretrospectivesurveysformeasuringmortalityofhighlyclustereddiseasescasestudyofthe201416ebolaoutbreakinbodistrictsierraleone AT helenaweiss methodologicalissuesofretrospectivesurveysformeasuringmortalityofhighlyclustereddiseasescasestudyofthe201416ebolaoutbreakinbodistrictsierraleone |