SOMS-2: translation into portuguese of the screening for Somatoform Disorders

Abstract

The diagnosis of Somatization Disorder (SD) requires the presence of somatic medically unexplained symptoms (MUS) which must be assessed so that organic diseases may be excluded. SOMS-2 is a self-report measure for SD that assesses medically unexplained symptoms by requiring participants to answer affirmatively and qualify any of the complaints as MUS, only if they have obtained from his doctor the opinion that the said complaint is not due to an organic disease. According to the authors, original SOMS-2 has a good internal consistency with Cronbach's a = .87 and a good correlation between selfratings and interview (r = .75). After obtaining the author's permission, translation from and into English has been made by experienced translators. The resulting questionnaire has been used on a small group of patients. Afterwards the items in which there were difficulties in understanding during the pretest were identified and experienced practitioners were asked for suggestions. The resulting version was answered by 123 primary health care patients (sample I). After some modifications of the SOMS-2, another group of 190 primary health care patients answered the questionnaire (sample II). Most patients, in the first sample, found it difficult to understand that, in order to answer affirmatively it was necessary to answer three questions: 1) is the symptom present? 2) has your doctor found no clear causes for the symptom? 3) does the symptom affect your well-being? The difficulties in understanding items 21 and 45 (pre-test) were confirmed. Items 11, 28 and 38 were more easily understood when worded differently. In sample I, less than 5% of positive answers were given to items 20, 21, 23, 40, 43, 45, and 51. Probably because of the low education level of the Portuguese population which this sample reflects, difficulties in carrying out the instructions given at the beginning made it advisable to modify the SOMS-2, so that the three implicit questions in each question of the SOMS-2 were divided into two columns (two explicit questions). Simultaneously attention must continue on controlling severity criterion (the third implicit question). After phase I, the items with an answer rate of less than 5% were eliminated. The majority of them are coincident with the low answer rate items found by the authors of the original version. The next step is to study the internal consistency and the correlation between results of self-ratings and interview, of the resulting version, in order to establish the validity of the SOMS-2 in these populations.