{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,10]],"date-time":"2026-02-10T18:10:17Z","timestamp":1770747017064,"version":"3.49.0"},"reference-count":7,"publisher":"S. Karger AG","issue":"3","license":[{"start":{"date-parts":[[2007,1,1]],"date-time":"2007-01-01T00:00:00Z","timestamp":1167609600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.karger.com\/Services\/SiteLicenses"},{"start":{"date-parts":[[2007,1,1]],"date-time":"2007-01-01T00:00:00Z","timestamp":1167609600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/www.karger.com\/Services\/SiteLicenses"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Neuroepidemiology"],"published-print":{"date-parts":[[2007]]},"abstract":"<jats:p>&lt;i&gt;Background\/Aims:&lt;\/i&gt; Health outcomes research often uses administrative databases. Patients with the diseases of interest are identified using International Classification of Diseases (ICD-9 CM) codes. The utility of the code for essential tremor (ET), 333.1, remains untested. We determined the positive predictive value (PPV) of the code 333.1. &lt;i&gt;Methods:&lt;\/i&gt; Patients with the ICD-9 CM code 333.1 were identified from billing records at the Neurological Institute of New York. Their medical records were reviewed to determine whether they met Consensus Criteria for ET. &lt;i&gt;Results:&lt;\/i&gt; Of 964 patients who carried the code 333.1, only 472 met diagnostic criteria for ET (i.e. PPV = 49.0%). The additional use of ICD 9-CM codes for parkinsonism and dystonia (as exclusionary criteria) only marginally improved this value (57.8%). Common diagnoses among the false positives were Parkinson\u2019s disease, dystonia, enhanced physiological tremor, drug-induced tremor, orthostatic tremor, and psychogenic tremor. Patients seen by general neurologists (vs. movement disorder specialists) were half as likely to meet diagnostic criteria for ET (34.6 vs. 51.9%, OR 0.50, 95% CI 0.23\u20130.70, p &lt; 0.001). &lt;i&gt;Conclusion:&lt;\/i&gt; The code 333.1 performed poorly when attempting to identify ET cases. Given the very high prevalence of ET, a unique diagnostic code would seem to be in order.<\/jats:p>","DOI":"10.1159\/000104096","type":"journal-article","created":{"date-parts":[[2007,6,20]],"date-time":"2007-06-20T09:40:14Z","timestamp":1182332414000},"page":"181-185","source":"Crossref","is-referenced-by-count":11,"title":["ICD-9 CM Code 333.1 as an Identifier of Patients with Essential Tremor: A Study of the Positive Predictive Value of This Code"],"prefix":"10.1159","volume":"28","author":[{"given":"Elan D.","family":"Louis","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"LaKeisha M.","family":"Applegate","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eileen","family":"Rios","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"127","published-online":{"date-parts":[[2007,6,19]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","DOI":"10.1159%2F000074508"},{"key":"ref2","doi-asserted-by":"publisher","DOI":"10.1002%2Fmds.10333"},{"key":"ref3","doi-asserted-by":"publisher","DOI":"10.1002%2F1531-8257%28200005%2915%3A3%3C439%3A%3AAID-MDS1004%3E3.0.CO%3B2-F"},{"key":"ref4","doi-asserted-by":"publisher","DOI":"10.1002%2Fmds.20479"},{"key":"ref5","doi-asserted-by":"publisher","DOI":"10.1212%2F01.wnl.0000172352.88359.2d"},{"key":"ref6","doi-asserted-by":"publisher","DOI":"10.1002%2Fmds.20565"},{"key":"ref7","doi-asserted-by":"publisher","DOI":"10.1002%2Fmds.10376"}],"container-title":["Neuroepidemiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/104096","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/104096","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,4,24]],"date-time":"2025-04-24T02:51:55Z","timestamp":1745463115000},"score":1,"resource":{"primary":{"URL":"https:\/\/karger.com\/article\/doi\/10.1159\/000104096"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2007]]},"references-count":7,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2007,8,1]]}},"URL":"https:\/\/doi.org\/10.1159\/000104096","archive":["Portico"],"relation":{},"ISSN":["0251-5350","1423-0208"],"issn-type":[{"value":"0251-5350","type":"print"},{"value":"1423-0208","type":"electronic"}],"subject":[],"published":{"date-parts":[[2007]]}}}