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Identification of clinically important PECODR elements within medical journal abstracts P atient-population-problem, E xposure-intervention, C omparison, O utcome, D uration, & R esults. Martin Dawes, Pierre Pluye, Laura Shea, Roland Grad, Arlene Greenberg, Jian-Yun Nie.
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Identification of clinically important PECODR elements within medical journal abstractsPatient-population-problem, Exposure-intervention, Comparison, Outcome, Duration, & Results Martin Dawes, Pierre Pluye, Laura Shea, Roland Grad, Arlene Greenberg, Jian-Yun Nie
Evidence-Based Practice • See a patient • Have a question • Sometimes seek an answer • Firstly in secondary sources • E-B synopses eg GAC guidelines • Secondly in primary sources • Medline
Questions Unstructured = Unanswerable Make them structured • P Do women > 50 years • E taking calcium • C compared to women taking nothing • O have fewer hip fractures • D over 5 years • R NNT of 30
PROBLEMS - SOLUTIONS - QUESTION Problems • Too much information • Information keeps changing Solutions • Filters for evidence • MESH & PubMed clinical queries Questions • Would PECODR indexing the clinical literature help me find information for my patient? • Can we identify PECODR elements in abstracts? • Would the words or groups of words used help us to automatically do this?
METHODS Pilot study Convenience sample (N = 40) • 20 research articles (Evidence Based Medicine synopses) • 20 corresponding abstracts(PubMed) Converted the information into a text file Analyse the content: Qualitative and Quantitative
Methods • 6 themes defined: P, E, C, O, D, R • Extract text and allocate to a themes • extracts made from a word or words, • made up from a series of characters (the gold standard denominator) • Independently by two researchers • 10 rules developed iteratively eg exclusive assignment « 1 extract 1 theme »
Coding <R> Despite major differences <O> in blood pressure lowering, <R> there were no <O> outcome <R> differences <E> between atenolol <C> and placebo in the four studies, <P> comprising 6825 patients, <D> who were followed up for a mean of 4·6 years Should this be coded under C?
Quantitative Analysis So the method of coding seems to work 6 « PECODR » themes
QuantitativeAnalysis 1. For each theme PECODR Identification (inductive) of potential patterns or series of words Compare theme patterns comparison, compare, compared, comparing, etc, 2. For each pattern Only for those with a pattern frequency of > 70% found in the themes
Results: PECODR by abstracts & synopses PECODR exists in abstracts docs extracts docs extracts P 19 89 20 116 E 20 163 20 180 C 18 92 19 120 O 20 169 20 187 D 15 36 18 45 R 20 210 20 187 Total 759 835
RESULTS • P = Patient-population-problem No pattern: Example, diabetic E = Exposure-intervention No pattern: Example, Amoxil
4 more occurrences of the word “comparing” were in parts of the text that were not C extracts All were in C extracts RESULTS • C = Comparison: number of extracts assigned to C with C pattern and % of total C extracts found not assigned to C
RESULTS • O = « Outcome »: number of extracts assigned to O with O pattern and % of total O extracts found not assigned to O
RESULTS • R = Results: number of extracts assigned to R with R pattern and % of total R extracts found not assigned to R
RESULTS R (more) Significance
Results Summary Presence of text or text patterns • PECODR elements are present in the majority of abstracts with the exception of Duration (75%) Patterns of PECODR • P & E = Medical or Drug Terms (thesaurus) • The other element related extracts contain some patterns
DISCUSSION Limits • Pilot Study (N=40) • Exploratory study (rules developed iteratively for text extraction/ qualitative pattern identification) • Further Research • Textual Analysis using clever software with UdM to better identify patterns • Larger sample of papers • Do GP’s want a PECODR search engine?
CONCLUSION • Possible standard textual patterns (lexico-semantics) may help automatically determine PECODR elements • If this is possible we may be able to develop a prototype of new technology for automatic information retrieval (aspectual Search Engine) • To index the clinical information according to needs' for the users (eg family practitioners) • That will help people answer clinical questions…maybe
Cost Effectiveness 1,300 Problem/Patient Select Exposure Select Outcome Select Duration Old/Adult/Young Diagnosis12,000 Heart attacks 2,300 Harm 1,780 Insulin 12,000 Mortality 60 >3 years n=20 Antihypertensive 6,000 DIABETIC Therapy 28,000 Oral Hypoglycaemics 1,780 • NNT 25 4.6 years • NNT 34 4.2 years • N/A • NNT 54 1.8 years • NNT 35 N/A Prognosis 2,000 Male/Female Aetiology 4000 Number under each heading represents articles Martin Dawes