{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,8]],"date-time":"2026-04-08T18:10:34Z","timestamp":1775671834193,"version":"3.50.1"},"reference-count":38,"publisher":"Wiley","issue":"6","license":[{"start":{"date-parts":[[2021,3,26]],"date-time":"2021-03-26T00:00:00Z","timestamp":1616716800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Euro J of Neurology"],"published-print":{"date-parts":[[2021,6]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Background and purpose<\/jats:title><jats:p>There is concern that the Patient Health Questionnaire\u20109 (PHQ\u20109) depression scale may be impacted by the presence of somatic symptoms (differential item functioning [DIF]) in patients with neurological conditions. We evaluated the PHQ\u20109 for the presence and impact of DIF in large clinical samples of neurological patients.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>We conducted a cross\u2010sectional study of patients seen at the Cleveland Clinic Cerebrovascular, Headache, Movement Disorder, and Neuromuscular clinics who completed the PHQ\u20109 and patient\u2010reported disease severity measures as part of standard care between 29 July 2008 and 21 February 2013. We evaluated PHQ\u20109 items for DIF with respect to disease\u2010specific severity for each condition. Salient DIF impact was characterized as a difference between DIF\u2010adjusted and unadjusted PHQ\u20109 scores.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Included in the study were 2112 patients with stroke, 8221 with migraine, 440 with amyotrophic lateral sclerosis (ALS), and 5022 with Parkinson disease (PD). Several PHQ\u20109 items demonstrated DIF with respect to disease\u2010specific severity, although salient DIF was present in very few patients (stroke, <jats:italic>n<\/jats:italic>\u00a0=\u00a00; migraine, <jats:italic>n<\/jats:italic>\u00a0=\u00a01; ALS, <jats:italic>n<\/jats:italic>\u00a0=\u00a013; PD, <jats:italic>n<\/jats:italic>\u00a0=\u00a01).<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>PHQ\u20109 items function consistently across disease severity, with salient levels of DIF impact found only for a very small proportion of people. These results suggest that the PHQ\u20109 provides a consistent measure of depression severity among people with neurological conditions associated with somatic symptoms that overlap with depression.<\/jats:p><\/jats:sec>","DOI":"10.1111\/ene.14822","type":"journal-article","created":{"date-parts":[[2021,3,14]],"date-time":"2021-03-14T06:13:52Z","timestamp":1615702432000},"page":"1812-1819","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Somatic symptoms have negligible impact on Patient Health Questionnaire\u20109 depression scale scores in neurological patients"],"prefix":"10.1111","volume":"28","author":[{"given":"Irene L.","family":"Katzan","sequence":"first","affiliation":[{"name":"Cerebrovascular Center Neurological Institute Cleveland Clinic Cleveland Ohio USA"},{"name":"Center for Outcomes Research and Evaluation Neurological Institute Cleveland Clinic Cleveland Ohio USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4314-2282","authenticated-orcid":false,"given":"Brittany","family":"Lapin","sequence":"additional","affiliation":[{"name":"Center for Outcomes Research and Evaluation Neurological Institute Cleveland Clinic Cleveland Ohio USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sandra","family":"Griffith","sequence":"additional","affiliation":[{"name":"Center for Outcomes Research and Evaluation Neurological Institute Cleveland Clinic Cleveland Ohio USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lara","family":"Jehi","sequence":"additional","affiliation":[{"name":"Epilepsy Center Neurological Institute Cleveland Clinic Cleveland Ohio USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hubert","family":"Fernandez","sequence":"additional","affiliation":[{"name":"Center for Neurological Restoration Neurological Institute Cleveland Clinic Cleveland Ohio USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0737-6065","authenticated-orcid":false,"given":"Erik","family":"Pioro","sequence":"additional","affiliation":[{"name":"Neuromuscular Center Neurological Institute Cleveland Clinic Cleveland Ohio USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Stewart","family":"Tepper","sequence":"additional","affiliation":[{"name":"Center for Neurological Restoration Neurological Institute Cleveland Clinic Cleveland Ohio USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Paul K.","family":"Crane","sequence":"additional","affiliation":[{"name":"Division of General Internal Medicine University of Washington Seattle Washington USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2021,3,26]]},"reference":[{"key":"e_1_2_7_2_1","doi-asserted-by":"publisher","DOI":"10.1136\/jnnp.2011.245779"},{"key":"e_1_2_7_3_1","doi-asserted-by":"publisher","DOI":"10.1136\/jnnp.2010.230862"},{"key":"e_1_2_7_4_1","doi-asserted-by":"publisher","DOI":"10.1136\/jnnp.74.6.817"},{"key":"e_1_2_7_5_1","doi-asserted-by":"publisher","DOI":"10.1161\/STR.0000000000000158"},{"key":"e_1_2_7_6_1","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.0b013e3182a956bf"},{"key":"e_1_2_7_7_1","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.0000000000001965"},{"key":"e_1_2_7_8_1","doi-asserted-by":"publisher","DOI":"10.1161\/STR.0b013e3181e7512b"},{"key":"e_1_2_7_9_1","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.0000000000001448"},{"key":"e_1_2_7_10_1","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.0000000000002670"},{"key":"e_1_2_7_11_1","doi-asserted-by":"publisher","DOI":"10.1046\/j.1525-1497.2001.016009606.x"},{"issue":"8","key":"e_1_2_7_12_1","first-page":"508","article-title":"Depression: screening and diagnosis","volume":"98","author":"Maurer DM","year":"2018","journal-title":"Am Fam Physician"},{"key":"e_1_2_7_13_1","doi-asserted-by":"publisher","DOI":"10.1161\/STR.0000000000000113"},{"key":"e_1_2_7_14_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jad.2015.05.059"},{"key":"e_1_2_7_15_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1528-1167.2011.03276.x"},{"key":"e_1_2_7_16_1","doi-asserted-by":"publisher","DOI":"10.1080\/13854040802003299"},{"key":"e_1_2_7_17_1","doi-asserted-by":"publisher","DOI":"10.1590\/2237-6089-2015-0030"},{"key":"e_1_2_7_18_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.genhosppsych.2015.06.007"},{"key":"e_1_2_7_19_1","first-page":"683","article-title":"The Knowledge Program: an innovative, comprehensive electronic data capture system and warehouse","volume":"2011","author":"Katzan I","year":"2011","journal-title":"AMIA Annu Symp Proc"},{"key":"e_1_2_7_20_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.genhosppsych.2010.03.006"},{"key":"e_1_2_7_21_1","doi-asserted-by":"publisher","DOI":"10.1097\/01.mlr.0000245183.28384.ed"},{"key":"e_1_2_7_22_1","doi-asserted-by":"publisher","DOI":"10.18637\/jss.v039.i08"},{"key":"e_1_2_7_23_1","doi-asserted-by":"publisher","DOI":"10.1007\/s11136-011-9882-y"},{"key":"e_1_2_7_24_1","volume-title":"Principles and Practice of Structural Equation Modeling","author":"Kline R","year":"2011"},{"key":"e_1_2_7_25_1","doi-asserted-by":"publisher","DOI":"10.1187\/cbe.18-04-0064"},{"key":"e_1_2_7_26_1","doi-asserted-by":"publisher","DOI":"10.1007\/s11136-007-9185-5"},{"key":"e_1_2_7_27_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0895-4356(99)00071-2"},{"issue":"2","key":"e_1_2_7_28_1","first-page":"127","article-title":"Extension of an iterative hybrid ordinal logistic regression\/item response theory approach to detect and account for differential item functioning in longitudinal data","volume":"55","author":"Mukherjee S","year":"2013","journal-title":"Psychol Test Assess Model"},{"key":"e_1_2_7_29_1","doi-asserted-by":"publisher","DOI":"10.1161\/01.STR.0000155688.18207.33"},{"key":"e_1_2_7_30_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1600-0447.2010.01558.x"},{"key":"e_1_2_7_31_1","doi-asserted-by":"publisher","DOI":"10.7224\/1537-2073.2017-069"},{"key":"e_1_2_7_32_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.apmr.2010.12.008"},{"key":"e_1_2_7_33_1","doi-asserted-by":"publisher","DOI":"10.1111\/pme.12537"},{"key":"e_1_2_7_34_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1532-5415.1993.tb07298.x"},{"key":"e_1_2_7_35_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1600-0447.1983.tb09716.x"},{"key":"e_1_2_7_36_1","doi-asserted-by":"publisher","DOI":"10.1186\/1477-7525-9-82"},{"key":"e_1_2_7_37_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.genhosppsych.2018.03.009"},{"key":"e_1_2_7_38_1","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.0000000000002465"},{"key":"e_1_2_7_39_1","doi-asserted-by":"publisher","DOI":"10.1093\/ageing\/aft065"}],"container-title":["European Journal of Neurology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/ene.14822","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/full-xml\/10.1111\/ene.14822","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/ene.14822","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,9,2]],"date-time":"2023-09-02T01:10:16Z","timestamp":1693617016000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/ene.14822"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,3,26]]},"references-count":38,"journal-issue":{"issue":"6","published-print":{"date-parts":[[2021,6]]}},"alternative-id":["10.1111\/ene.14822"],"URL":"https:\/\/doi.org\/10.1111\/ene.14822","archive":["Portico"],"relation":{},"ISSN":["1351-5101","1468-1331"],"issn-type":[{"value":"1351-5101","type":"print"},{"value":"1468-1331","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,3,26]]},"assertion":[{"value":"2021-02-23","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2021-03-05","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2021-03-26","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}