Creation of a severity index for hidradenitis suppurativa that includes a validated quality-of-life measure: the HIDRAscore

Background. Hidradenitis suppurativa (HS) is a chronic, debilitating disease with a considerable\r\neffect on patient quality of life. Its clinical severity can be measured using different scoring\r\nsystems; however few of them include patient-centred parameters.\r\nObjective. To create a new scoring system for HS that includes a quality-of-life instrument, the\r\nHIDRAdisk.\r\nMethods. This post-hoc analysis was carried out within the framework of a multicentre,\r\nlongitudinal, epidemiologic study conducted over 9 months on quality-of-life aspects of HS. The\r\nnew severity score was created using as reference a question from the Subject Satisfaction\r\nQuestionnaire (SSQ) concerning the severity of HS as evaluated by the patient. Associated\r\nvariables were selected using univariable and multivariable logistic regression models. The\r\ndiscriminant capabilities of the final model and of the final score were evaluated by the area under\r\nthe receiver operating characteristic curve and the Hosmer-Lemeshow test.\r\nResults. The study population included 308 patients with HS of any severity grade. According to\r\nthe results of the regression models, the variables associated with the reference SSQ measure were\r\nnumber of inflammatory nodules, abscesses and draining fistulas; the HIDRAdisk score; and the\r\nnumber of subumbilical lesions. The HIDRAscore is obtained by the sum of the scores associated\r\nwith the number of these parameters. Possible scores range from 0 to 10.\r\nConclusion. The HIDRAscore is a new scoring system for HS severity which, in addition to the\r\nclinical evaluation by the physician, includes a validated patient-reported outcome measure, the\r\nHIDRAdisk.