Table 2.

Comparison of manual coding results for 1,000 search failures from each of two consumer health information systems. (Since queries are often multiply coded, the total number of codings exceeds the total number of queries.)

Code	Description	Clinical Trials.gov	MEDLINE plus	Examples
A	In Scope Error-free Coded with ≥ 1 B code Total	296 582 878	274 491 765	veterinary cancer trials, National Coverage Decision, infant mortality rate, reiter’s syndrome
B1	Misspelling	268	163	apashia, artories, DIABETIES, mavulur degeneration, pulmanary fibrosis, multile sclerosis
B2	Abbreviation	8	9	pt, dx, tx, dr., Calif, MA
B3	Non-alphanumeric	207	139	+ % / _ " ; : ' ? *
B4	Run-together Phrase	31	12	use of energy healing, lymes disease, look ahead trial vaccines and periodontal disease
B5	Word/Phrase Split Inappropriately	25	11	myco bacterium; bi, polar disorder; cartilage, replacement; arthritis, rheumatoid; Barre-Guillain
B6	Search Operator	147	136	and, or, vs, not, NAC+bronchitis, non-hodgkins lympoma/New jersey; NEAR
B7	Unordered List of Words	48	63	Topotecan Gemcitabine lung, antegren multiple sclerosis, allergy peanut
B8	Truncation	5	8	neuro, sarco, naltrexon*, ENAXO*
B9	Ellipsis	44	46	Downs [syndrome]; hoxsey [therapy]; prinzmetals [angina]; [Citrus] aurantium; afasak [study]
B10	Natural Language Phrase	92	79	atlas of orthosis; What does beer do to your bones?; accurate assessment of precision errors
B11	Acronym	76	47	EPA, hplc, VIN, adh, C225, efc 4584, FR901228, CHARM, imac, PKD, TS-1
B12	Possible Consumer Term	36	36	nose bleed, no feeling in legs, crooked spine, implantable minimized telescope, tubes tied
H	Web Address	2	3	ucsf.edu/research/trials; w.w.w.washington e.d.u.
L	Language other than English	16	39	fase 3; vitamina C; malignes, Pleuramesotheliom, cardiopathies valvulaires
P	Publication	0	10	N. ENG. J. mED 2000 343: 16–22, urology october issue, nejm,
U	Unknown, Uncertain or Out of Scope	117	191	rastetieds, calciomimeticagew, Carreca, bargar, J4, NuVue, pea poisson, resources allocation, drum