Searching the Literature

Transcription

1 Dhaka, December 2012 Searching the Literature John Eyers 3ie IDCG

2 The Search Process Read through Protocol familiarise terminologies, study methods, date limits, language restrictions, look through refs for potential keywords Identify potential databases and websites to be searched subject-specific, multidisciplinary See Cochrane LMIC databases list, Hammerstrøm et al Specialist libraries LSE, Harvard etc Campbell/Cochrane published SRs Grey literature Sources

3 The Search Process Prepare strategy customised for each database need to account for terminology differences across disciplines, and different database search platforms Searches should aim for high sensitivity to retrieve all relevant papers precision likely to be low Larger number of papers likely to be retrieved Hand searching selected journals snowballing back through ref lists & contacting others in field Citation searches of included studies using Web of Science, Google Scholar

4 Search Strategy What to Include? Interventions/study methods being assessed Geographical limits LMICs, Africa (World Bank list, Cochrane EPOC LMICs list? Language/time period limits of publications? Age Groups? Use thesaurus terms/textwords Does database have thesaurus/subject headings (Controlled language/vocabulary)? Identify relevant subject headings How are relevant papers indexed in database?

5 Search Strategy Free text/natural language searching - Identify textwords in title/abstract Synonyms (buy, purchase; speedy, quick) US/UK Spellings (behavior, behaviour) Truncation/stemming (effect*, adolescen*) Position truncation symbol correctly immuni*, immuniz*, immunis*

6 Combining concepts together Boolean Operators OR, AND, NOT Avoid NOT where possible (eg Tanzania NOT Kenya will remove papers about both countries) Proximity/Adjacency Operators NEAR, WITHIN, ADJ Operators will vary between databases Eg Infant* adj3 Care

7 PsycINFO example on Parent Involvement - Selecting Free Text Terms and Descriptors for PsycINFO Descriptors: Parent involvement See: Parent-school relationship Related descriptors: Parenting style; Parental role; Parents; Involvement; Participation Relevant free text terms: parent* involvement; parent* practices; parent* behaviours Descriptors: Academic performance See: Academic achievement Classification Code: Academic-Learning-and-Achievement Descriptors: Elementary school children See: Elementary school Age Group: Childhood (birth-12-yrs); School-Age (6-12-yrs)

8 Pubmed/Medline Indexes approx peer-reviewed journals Heavy bias in favour of Western medicine only about 30 African journals included Thesaurus/Medical Subject Headings (MeSH) 20,000 headings covering diseases, organisms, survey methods, geographics etc, all placed in a Tree structure reflecting broader/narrower terms

9 MeSH Terms (Diseases) HIV Infections Acquired Immunodeficiency Syndrome AIDS-associated Nephropathy AIDS Arteritis, CNS AIDS Dementia Complex AIDS-Related Complex AIDS-Related Opportunistic Infections HIV-Associated Lipodystrophy Syndrome HIV Enteropathy HIV Seropositivity HIV Wasting Syndrome

10 MeSH Terms (Stats & Economics) Regression Analysis Least-Squares Analysis Linear Models Logistic Models Proportional Hazards Models Costs and Cost Analysis Cost Allocation Cost-Benefit Analysis Cost Control Cost Savings Cost of Illness..etc

11 MeSH Terms (Geographic) Africa South of the Sahara Africa, Eastern Burundi Djibouti Eritrea Ethiopia Kenya Rwanda Somalia Sudan Tanzania Uganda..etc

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13 Search Examples 1. Improving enrollment in primary and secondary school children (try ERIC - free education database, and IDEAS (Repec) economic research database) 2. Farmer field schools for improving farming practice in LMICs (try AgEcon or Agricola or Google Scholar) 3. Strategies for prevention in adolescent sexual behaviour (Try Popline or WHO Reproductive Health Library or Pubmed) 4. Logon to Hinari and find a special issue on SRs in Journal of Development Effectiveness. Is it available full-text on Hinari? 5. Investigate AGORA and OARE via Hinari what are they?

14 Further Search Examples 1. The impact of cash transfers in improving health outcomes in LMICs Cochrane Library?, 3ie s SRs Database?, ELDIS? 2. Improving water and sanitation in the prevention of diarrhoeal disease Try the Regional indexes of WHO s Global Health Library 3. Community-based disability rehabilitation practices in Bangladesh Campbell Library? AskSource 4. How many papers are there on the Grameen Bank in ELDIS?

15 References 1. Wade CA et al. (2006). Information retrieval and the role of the information scientist in producing high quality systematic reviews in the social, behavioural, and education sciences. Evidence & Policy: A Journal of Research, Debate and Practice 2(1), Hammerstrøm, K et al. (2010). Searching for studies: A guide to information retrieval for Campbell systematic reviews. Suppl 1. Campbell Collaboration information_retrieval_guide.php 3. Eyers, JE. (1998). Searching bibliographic databases effectively. Health Policy and Planning 13(3), ( )

16 Contact me this week, or afterwards if you need help : johneyers@hotmail.com

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