Search Techniques for Therapy, Diagnosis, Prognosis, and Etiology Questions: Sophisticated Search Options for Retrieving Evidence

USING ELEMENTS OF ETIOLOGY HEDGES

Is your clinical question an ETIOLOGY question?

Incorporate elements of an etiology hedge into your search to find evidence that discusses causes of a disease or condition. You can also find etiology evidence by identifying specific causative agents such as microorganisms, environmental and social factors, and personal habits.

Recommended Etiology Subject Headings

Cross-sectional Studies
Odds Ratio
Risk
Risk Factors
Analytic Studies
Case-control Studies
Retrospective Studies
Cohort Studies
Longitudinal Studies
Prospective Studies
Follow-up Studies

Recommended Etiology Subheadings (attach to subject)

etiology (et)
chemically induced (ci)

Recommended Etiology Keyword Searches

Try entering these combinations on the "enter keyword" line:

(risk$ or cohort$ or follow-up or predict$ or case control$).ti,ab,sh.
(case control).ti,ab,sh.
(cause$ or causat$ or causing or causal$ or etiol$).ti,ab,sh.

The .ti,ab,sh. that you see above indicate that you are looking for these words in the titles (ti) , abstracts (ab), or subject headings (sh) of the articles. The $ indicates a wild card character or truncation.

ETIOLOGY HEDGE EXAMPLE:
This strategy will retrieve evidence that discusses the causes or etiology of asthma.

# Search History Results Comments

1 exp *asthma/ci 178 Here we've specified "chemically induced" (/ci) asthma using the appropriate subheading. The are 178 articles on chemically induced asthma.

2 exp *asthma/et 522 Here we've specified the "etiology" (/et) of asthma using the appropriate subheading. The are 522 articles, however, which is still an inappropriately large group. Let's combine this group with other useful keywords and subject headings to see what we find.

3 (case control).ti,ab,sh. 5969 Now we will search for "case control" finding nearly 6000 articles.

4 2 and 3 16 When we combine sets #2 (etiology of asthma) with #3 (case control) we find 16 articles.

5 cohort studies 12029 Now we're searching for a very specific type of study -- a "cohort study".

6 2 and 5
18 This combination of sets identifies 18 cohort studies on the etiology of asthma.

A variety of additional combinations can be used. Simply identify the disease state, and combine with it the most relevant recommended subject headings, subheadings, and keywords.

You can also incorporate into your search the specific cause of the disease, such as a certain drug, chemical, environmental factor, etc.

The strategy below will retrieve evidence that discusses asthma that is caused by cigarette smoking or exposure to tobacco smoke.

# Search History Results Comments

1 exp *asthma/et 522 Here we've specified the "etiology" (/et) of asthma using the appropriate subheading.

2 exp *smoking/ 4960 Here we've specified the causitive factor -- smoking.

3 1 and 2 16 By combining sets #1 and 2, we've identified articles that discuss smoking as a cause of asthma.

4 exp *asthma/ 7294 In this set, we are searching for asthma without attaching any subheadings to it. Notice that we've retrieved a large group of 7294 articles. Compare this group to set #1 where we used the etiology( /et ) subheading and found a much smaller group of 522 articles.

5 2 and 4 56 By combining sets #2 (smoking) and #4 (asthma without any subheadings), we've identified 56 articles that discuss the association between asthma and smoking. If you compare this group to the results of set #3, you'll see that this broader approach yields more articles.

#	Search History	Results	Comments
1	exp *asthma/et	522	Here we've specified the "etiology" (/et) of asthma using the appropriate subheading.
2	exp *smoking/	4960	Here we've specified the causitive factor -- smoking.
3	1 and 2	16	By combining sets #1 and 2, we've identified articles that discuss smoking as a cause of asthma.
4	exp *asthma/	7294	In this set, we are searching for asthma without attaching any subheadings to it. Notice that we've retrieved a large group of 7294 articles. Compare this group to set #1 where we used the etiology( /et ) subheading and found a much smaller group of 522 articles.
5	2 and 4	56	By combining sets #2 (smoking) and #4 (asthma without any subheadings), we've identified 56 articles that discuss the association between asthma and smoking. If you compare this group to the results of set #3, you'll see that this broader approach yields more articles.