Study Evaluating the Cost of the Treatments of the Refractory Psoriatic Arthritis to the Conventional Therapy

Overall cost per participant per month was evaluated as part of health economics evaluation to quantify burden of Refractory PsA and its treatment, resources absorbed by the disease and its care into monetary terms. Overall cost was defined as sum of direct and indirect costs (productivity losses). Direct costs included cost of following cost variables: pharmacological treatment; hospitalizations; diagnostic examinations, laboratory analysis and specialist visits; transports.

Overall cost per participant per month was evaluated as part of health economics evaluation to quantify burden of Refractory PsA and its treatment, resources absorbed by the disease and its care into monetary terms. Overall cost was defined as sum of direct and indirect costs (productivity losses). Direct costs included cost of following cost variables: pharmacological treatment; hospitalizations; diagnostic examinations, laboratory analysis and specialist visits; transports.

ICER: ratio of the incremental cost of treatment over the incremental effectiveness. Incremental cost = difference in cost between baseline and month 60. Effectiveness was defined as quality adjusted life year (QALY) gained, i.e. difference in Euro Quality of Life 5 Dimension (EQ-5D)- health state profile utility score between baseline and month 60. (EQ-5D: participant rated questionnaire to assess health-related quality of life in terms of a single utility score. Total score range -0.594 to 1.000; higher score indicates a better health state.)

ASAS measures symptomatic improvement in Ankylosing Spondylitis (AS) participants. ASAS = 4 domains: participant global assessment of disease activity, pain, function, inflammation. ASAS 20 = 20% improvement from baseline and an absolute change >= 10 units on a 0-100 scale (0=no disease activity; 100=high disease activity) for >= 3 domains, and no worsening in remaining domain.

PsARC is comprised of 4 clinical improvement criteria: 1 unit (0-5 Likert scale) improvement on the Physician Global Assessment (PGA); 20% (0-100 scale) improvement on the participant assessments; and 30% reduction in the number of tender joints; and 30% reduction in the number of swollen joints. To achieve a clinical response, the participant must improve in 2 of the 4 PsARC criteria, 1 of which has to be the number of tender or swollen joints and none of the 4 scores could worsen.

Combined assessment of lesion severity and area affected into single score. Body was divided into 4 sections: head, arms, trunk, legs. For each section, percent area of skin involved was estimated: 0= 0% to 6= 90-100%. Severity was estimated by clinical signs: erythema, induration, desquamation; scale: 0= none to 4= maximum. Final PASI = sum of severity parameters for each section*area score*weight of section (head: 0.1, arms: 0.2, body: 0.3, legs: 0.4); total possible score range: 0= no disease to 72= maximal disease.

BASFI is a validated self assessment tool that determines the degree of functional limitation in AS. Utilizing a Visual Analog Scale (VAS) of 0-10 (0 = easy, 10 = impossible), participants answered 10 questions assessing their ability in completing normal daily activities or physically demanding activities. The BASFI score is a sum of the scores of the 10 questions. Total possible score range: 0-100, where higher score referred to higher impairment in the functional ability.

BASDAI is a validated self assessment tool used to determine disease activity in participant with Ankylosing Spondylitis (AS). Utilizing a VAS of 0-10 (0=none and 10=very severe) participant's answered 6 questions measuring discomfort, pain and fatigue. The final BASDAI score averages the individual assessments for a final score range of 0-10.

BASRI- Radiographs of participants with AS were scored using the New York criteria for the sacroiliac joints on a scale of 2 to 4, the lumbar and cervical spine on a scale of 0 to 4 (0 = normal, 1 = suspicious, 2 = mild, 3 = moderate, 4 = severe). These 3 scores were added together to produce the BASRI-spine (BASRI-s) score (range 2 to 12). Similarly, hip joints were scored on a scale of 0 to 4 to give BASRI-hip (BASRI-h). Sum of BASRI-s and BASRI-h produced BASRI-total (BASRI-t) score; total range 2 to 16, higher score represented worse health state.

Measurement in centimeters (cm) of the distance between marks originally placed while the participant was standing erect 10 cm above and 5 cm below the midpoint of a line that joints the posterior superior iliac spines. Distance between marks was re-measured with participant maximally bend forward, knees fully extended, with spine in full flexion.

Chest expansion, measured in cm, is defined as the difference in thoracic circumference during full expiration versus full inspiration, measured at the fourth intercostal space (nipple line).

Occiput-to-wall distance: distance between the occiput (posterior or back portion of the head) and the wall when the participant stood with heels and shoulder against the wall and the back straight.

Assessment of enthesitis was performed in the following 7 domains: 1) 1st costochondral joint left and right, 2) 7th costochondral joint left and right, 3) posterior superior iliac spine left and right, 4) anterior superior iliac spine left and right, 5) iliac crest left and right, 6) 5th lumbar spinous process and 7) proximal insertion of Achilles tendon left and right. Each domain was graded for the presence (1) and absence (0) of tenderness yielding total MASES ranging from 0 (no tenderness) to 13 (worst possible score; severe tenderness).

Number of swollen joints was determined by examination of 66 joints and identifying when swelling was present. The number of swollen joints was recorded on the joint assessment form at each visit, no swelling = 0, swelling =1. Number of tender joints was determined by examining 68 joints and identified the joints that were painful under pressure or to passive motion. The number of tender joints was recorded on the joint assessment form at each visit, no tenderness = 0, tenderness = 1.

ACR20 response: greater than or equal to (>=) 20 percent (%) improvement in tender joint count; >= 20% improvement in swollen joint count; and >= 20% improvement in at least 3 of 5 remaining ACR core measures: participant assessment of pain; participant global assessment of disease activity; physician global assessment of disease activity; self-assessed disability (disability index of the Health Assessment Questionnaire [HAQ]); and C-Reactive Protein (CRP).

ACR50 response: >= 50% improvement in tender joint count; >= 50% improvement in swollen joint count; and >= 50% improvement in at least 3 of 5 remaining ACR core measures: participant assessment of pain; participant global assessment of disease activity; physician global assessment of disease activity; self-assessed disability (disability index of the HAQ); and CRP.

ACR70 response: >= 70% improvement in tender joint count; >= 70% improvement in swollen joint count; and >= 70% improvement in at least 3 of 5 remaining ACR core measures: participant assessment of pain; participant global assessment of disease activity; physician global assessment of disease activity; self-assessed disability (disability index of the HAQ); and CRP.

Radiographic score based on wassenberg consisted of 2 sub-scores, proliferation score (PS) assessing bone proliferation and destruction score (DS) assessing joint surface destruction. Score range for PS and DS was 0 to 160 (where higher score represented higher bone proliferation) and 0 to 200 (where higher score represented higher destruction), respectively. Total score = sum of PS and DS (range 0 to 360); higher score represented worse state.

Measured using a 100 millimeter (mm) VAS ranging from 0 mm = very good to 100 mm = very bad.

Physician Global Assessment of Disease Activity was measured on a 0 to 100 mm VAS, with 0 mm = no disease activity.

100 mm line (VAS) marked by participant. Intensity of pain range (over past week): 0 = no pain to 100 = worst possible pain.

ESR is a laboratory test that provides a non-specific measure of inflammation. The test assesses the rate at which red blood cells fall in a test tube. Normal range is 0-30 millimeter/hour (mm/hr). A higher rate is consistent with inflammation.

The test for CRP is a laboratory measurement for evaluation of an acute phase reactant of inflammation through the use of an ultrasensitive assay. A decrease in the level of CRP indicates reduction in inflammation and therefore improvement.

Duration of morning stiffness is defined as the time elapsed when participant woke up in the morning and was able to resume normal activities without stiffness in minutes (if none was present = 0; if morning stiffness was continuing, average of duration of stiffness over the past 3 days was reported; if stiffness persisted the entire day, 1440 minutes [24 hours*60 minutes] was recorded).

HAQ: participant-reported assessment of ability to perform tasks: 1) dress/groom; 2) arise; 3) eat; 4) walk; 5) reach; 6) grip; 7) hygiene; and 8) common activities over past week. Each item scored on 4-point Likert scale from 0 to 3: 0=no difficulty; 1=some difficulty; 2=much difficulty; 3=unable to do. Overall score was computed as the sum of domain scores and divided by the number of domains answered. Total possible score range 0-3 where 0 = least difficulty and 3 = extreme difficulty.

EQ-5D: participant rated questionnaire to assess health-related quality of life in terms of a single utility score. It assesses level of current health for 5 domains: mobility, self-care, usual activities, pain and discomfort, and anxiety and depression; 1 indicates better health state (no problems); 3 indicates worst health state ("confined to bed"). Scoring formula developed by EuroQol Group assigns a utility value for each domain in the profile. Score is transformed and results in a total score range -0.594 to 1.000; higher score indicates a better health state.

EQ-5D: participant rated questionnaire to assess health-related quality of life in terms of a single index value. The VAS component rates current health state on a scale from 0 mm (worst imaginable health state) to 100 mm (best imaginable health state); higher scores indicate a better health state.

SF-36 is a standardized survey evaluating 8 aspects of functional health and well being: physical and social functioning, physical and emotional role limitations, bodily pain, general health, vitality, mental health. The score for a section is an average of the individual question scores, which are scaled 0-100 (100=highest level of functioning) and was reported as 2 summary scores; Physical Component Score and Mental Component Score. Total score range for the summary scores = 0-100 where higher scores represented higher level of functioning.