Primary versus secondary source of data in observational studies and heterogeneity in meta-analyses of drug effects: a survey of major medical journals
Abstract Background The data from individual observational studies included in meta-analyses of drug effects are collected either from ad hoc methods (i.e. “primary data”) or databases that were established for non-research purposes (i.e. “secondary data”). The use of secondary sources may be prone...
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| Format: | Article |
| Language: | English |
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BMC
2018-09-01
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| Series: | BMC Medical Research Methodology |
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| Online Access: | http://link.springer.com/article/10.1186/s12874-018-0561-3 |
| _version_ | 1819154124588974080 |
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| author | Guillermo Prada-Ramallal Fatima Roque Maria Teresa Herdeiro Bahi Takkouche Adolfo Figueiras |
| author_facet | Guillermo Prada-Ramallal Fatima Roque Maria Teresa Herdeiro Bahi Takkouche Adolfo Figueiras |
| author_sort | Guillermo Prada-Ramallal |
| collection | DOAJ |
| description | Abstract Background The data from individual observational studies included in meta-analyses of drug effects are collected either from ad hoc methods (i.e. “primary data”) or databases that were established for non-research purposes (i.e. “secondary data”). The use of secondary sources may be prone to measurement bias and confounding due to over-the-counter and out-of-pocket drug consumption, or non-adherence to treatment. In fact, it has been noted that failing to consider the origin of the data as a potential cause of heterogeneity may change the conclusions of a meta-analysis. We aimed to assess to what extent the origin of data is explored as a source of heterogeneity in meta-analyses of observational studies. Methods We searched for meta-analyses of drugs effects published between 2012 and 2018 in general and internal medicine journals with an impact factor > 15. We evaluated, when reported, the type of data source (primary vs secondary) used in the individual observational studies included in each meta-analysis, and the exposure- and outcome-related variables included in sensitivity, subgroup or meta-regression analyses. Results We found 217 articles, 23 of which fulfilled our eligibility criteria. Eight meta-analyses (8/23, 34.8%) reported the source of data. Three meta-analyses (3/23, 13.0%) included the method of outcome assessment as a variable in the analysis of heterogeneity, and only one compared and discussed the results considering the different sources of data (primary vs secondary). Conclusions In meta-analyses of drug effects published in seven high impact general medicine journals, the origin of the data, either primary or secondary, is underexplored as a source of heterogeneity. |
| first_indexed | 2024-12-22T15:16:06Z |
| format | Article |
| id | doaj.art-9be0b16eca60416fa427c6bbe4f17448 |
| institution | Directory Open Access Journal |
| issn | 1471-2288 |
| language | English |
| last_indexed | 2024-12-22T15:16:06Z |
| publishDate | 2018-09-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Medical Research Methodology |
| spelling | doaj.art-9be0b16eca60416fa427c6bbe4f174482022-12-21T18:21:45ZengBMCBMC Medical Research Methodology1471-22882018-09-0118111410.1186/s12874-018-0561-3Primary versus secondary source of data in observational studies and heterogeneity in meta-analyses of drug effects: a survey of major medical journalsGuillermo Prada-Ramallal0Fatima Roque1Maria Teresa Herdeiro2Bahi Takkouche3Adolfo Figueiras4Department of Preventive Medicine and Public Health, University of Santiago de CompostelaResearch Unit for Inland Development, Polytechnic of Guarda (Unidade de Investigação para o Desenvolvimento do Interior - UDI/IPG)Department of Medical Sciences & Institute for Biomedicine – iBiMED, University of AveiroDepartment of Preventive Medicine and Public Health, University of Santiago de CompostelaDepartment of Preventive Medicine and Public Health, University of Santiago de CompostelaAbstract Background The data from individual observational studies included in meta-analyses of drug effects are collected either from ad hoc methods (i.e. “primary data”) or databases that were established for non-research purposes (i.e. “secondary data”). The use of secondary sources may be prone to measurement bias and confounding due to over-the-counter and out-of-pocket drug consumption, or non-adherence to treatment. In fact, it has been noted that failing to consider the origin of the data as a potential cause of heterogeneity may change the conclusions of a meta-analysis. We aimed to assess to what extent the origin of data is explored as a source of heterogeneity in meta-analyses of observational studies. Methods We searched for meta-analyses of drugs effects published between 2012 and 2018 in general and internal medicine journals with an impact factor > 15. We evaluated, when reported, the type of data source (primary vs secondary) used in the individual observational studies included in each meta-analysis, and the exposure- and outcome-related variables included in sensitivity, subgroup or meta-regression analyses. Results We found 217 articles, 23 of which fulfilled our eligibility criteria. Eight meta-analyses (8/23, 34.8%) reported the source of data. Three meta-analyses (3/23, 13.0%) included the method of outcome assessment as a variable in the analysis of heterogeneity, and only one compared and discussed the results considering the different sources of data (primary vs secondary). Conclusions In meta-analyses of drug effects published in seven high impact general medicine journals, the origin of the data, either primary or secondary, is underexplored as a source of heterogeneity.http://link.springer.com/article/10.1186/s12874-018-0561-3Observational studiesMeta-analysisSource of dataHeterogeneityDrugOver-the-counter |
| spellingShingle | Guillermo Prada-Ramallal Fatima Roque Maria Teresa Herdeiro Bahi Takkouche Adolfo Figueiras Primary versus secondary source of data in observational studies and heterogeneity in meta-analyses of drug effects: a survey of major medical journals BMC Medical Research Methodology Observational studies Meta-analysis Source of data Heterogeneity Drug Over-the-counter |
| title | Primary versus secondary source of data in observational studies and heterogeneity in meta-analyses of drug effects: a survey of major medical journals |
| title_full | Primary versus secondary source of data in observational studies and heterogeneity in meta-analyses of drug effects: a survey of major medical journals |
| title_fullStr | Primary versus secondary source of data in observational studies and heterogeneity in meta-analyses of drug effects: a survey of major medical journals |
| title_full_unstemmed | Primary versus secondary source of data in observational studies and heterogeneity in meta-analyses of drug effects: a survey of major medical journals |
| title_short | Primary versus secondary source of data in observational studies and heterogeneity in meta-analyses of drug effects: a survey of major medical journals |
| title_sort | primary versus secondary source of data in observational studies and heterogeneity in meta analyses of drug effects a survey of major medical journals |
| topic | Observational studies Meta-analysis Source of data Heterogeneity Drug Over-the-counter |
| url | http://link.springer.com/article/10.1186/s12874-018-0561-3 |
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