Cost-effectiveness and Cost-Utility Evaluation of the Individual vs. Group Transdiagnostic Psychological Treatment for Emotional Disorders in Primary Care (PsicAP-Costs)

Change in panic symptoms: Patient Health Questionnaire-Panic Disorder (PHQ-PD)

时间窗: Baseline, immediately after the intervention, and follow-ups (6 and 12 months)

The PHQ-PD is the specific panic disorder module of the PHQ and scores each DSM-IV criterion as "yes" or "no" (Wittkampf et al., 2011). Muñoz-Navarro et al. (2016) tested it in Spanish primary care settings and modified the original algorithm to increase the sensitivity for PD diagnosis: the most optimal cut-off point for screening purposes was 5 (the first item \[for panic screening\] and one of the following three, plus four somatic symptoms) (sensitivity of 77% and specificity of 72%).

Change in somatoform symptoms: 15-item Patient Health Questionnaire (PHQ-15)

时间窗: Baseline, immediately after the intervention, and follow-ups (6 and 12 months)

The PHQ-15 (Kroenke et al., 2002) is the somatization module of the PHQ. It includes 13 somatic symptoms plus 2 from the PHQ-9 (sleeping problems and fatigue). Scores of 5, 10, and 15 represent low, medium, and high somatic symptom severity, respectively. To screen a somatization disorder, whereas the original algorithm needs of at least a score of 2 in three or more somatic symptoms (sensitivity of 78% and specificity of 71%) (van Ravesteijn et al., 2009), the cut point usually used is 10; nevertheless, since this can be obtained with ten symptoms of mild severity, we decided to join both criteria to screen the disorder. Furthermore, an absence of biological cause is also often required (since PHQ-15 does not distinguish between medically explained and unexplained symptoms) (Kroenke et al., 2002), but the self-administered nature of the PHQ-15 makes difficult to determine this. The PHQ-15 has been validated with Spanish psychiatric outpatients (α = .78) (Ros et al., 2010).

Change in depression symptoms: 9-item Patient Health Questionnaire (PHQ-9)

时间窗: Baseline, immediately after the intervention, and follow-ups (6 and 12 months)

The PHQ-9 (Kroenke et al., 2001) is the depression module of the PHQ (Díez-Quevedo et al., 2001; Spitzer et al., 1999), that scores the 9 DSM-IV depression criteria present in the last two weeks from 0 ("not at all") to 3 ("nearly every day"). A score of 10 is usually set as the cut-off point for major depression disorder (MDD): a score of 10-14 indicates minor depression, moderate MDD, or dysthymia; 15-19, moderately severe MDD; and 20-27, severe MDD. This tool has been tested in Spanish primary care centres (McDonald's ω = .89) (Muñoz-Navarro, Cano-Vindel, Medrano et al., 2017), finding 12 as the best cut point for MDD diagnosis (sensitivity of 84% and specificity of 78%) compared with 10 (sensitivity of 95% and specificity of 67%).

Change in anxiety symptoms: 7-item General Anxiety Disorder scale (GAD-7)

时间窗: Baseline, immediately after the intervention, and follow-ups (6 and 12 months)

The GAD-7 (Spitzer et al., 2006) assesses common anxiety symptoms in the last two weeks, scoring from 0 ("not at all") to 3 ("nearly every day"). Cut points of 5, 10, and 15 represent mild, moderate, and severe anxiety, respectively. The algorithm sets 8 as the cut point for GAD, however it has been found that a score of 10 is more optimal (Spitzer et al., 2006). We will use the version validated by García-Campayo et al. (2010), that was recently tested in primary care centres (Cronbach's α = .83) (Muñoz-Navarro, Cano-Vindel, Moriana et al., 2017), confirming the score of 10 as the best diagnostic criterion (sensitivity of 87% and specificity of 78%).