Psoriasis treatment: Patients and doctors do not view Results the same way

How is the improvement according to the patient measured ?
-The improvement that the physician tells the patient (Objective measurements of psoriasis severity): Psoriasis Area Severity Index (PASI), Physician Global Assesment (PGA, Body Surface Area (BSA))
-The improvement the patient reports is measures using questionnaires (Patient Reported Outcomes (PRO):
Non specific scores: Dermatology Life Quality Index (DLQI)
Psoriasis specific scores: Psoriasis-Specific Symptom Assessment (PSSA), Symptom Diary or Inventory

A word on specific PROs
-Specific PROs are questionnaires developed by specific companies and need to obey certain rules:

• they need to ask the patients about their experience
• they must not require a long recollection period (usually not more than a year)
• they must not exceed 5 minutes to fill out

-Questionnaire characteristics:

• In the questionnaire by AMGEN (at the time of writing withdrew brodalumab recently):
  •  “pain” for doctors is asked through 3 different words: pain, stinging burning.
  •  the questionnaire asks the patient to grade  (mild, moderate, severe) itch redness scaling pain, flaking cracking stinging burning
  •  total improvement is when the score is equal to 0. Success is defined by a score of 2 or below . A DLQI score of 0 has been found in 75% of individuals achieving PASI 100 (two times more often than if clearance is incomplete (PASI improvement less than 100))
• Out of all questionnaires available from the industry (4 or 5), some do not include physical impairment (2 of them) or psychosocial impact (one of them)

In general Psoriasis impacts patients differently based on:
-gender: for a same severity score (PASI) women have a higher DLQI than men and often go to work without being functional (presenteeism)
-age
-location of lesions: DLQI scores are higher when Psoriasis is located on he Head and Neck. (as it is where the disease is visible to everyone else); Only if clearance is COMPLETE does the DLQI go back to 0. For other locations a PASI 75 improvement is enough for DLQI to go to 0

What is the proportion of dissatisfied patients when treatment is successful objectively ?
-A study done on 2259 patients with clear or almost clear psoriasis showed that:

• 22.5% had a subjective assessment discordant from physician objective scores.
• For instance for secukinumab (Cosentyx, Novartis), for a clearance of :
  • 90% (PASI 90), 75% are satisfied: note that is not 100%
  • 75-90%, 50% are satisfied
• less than 75%, 25% are satisfied

-Apart from the DLQI, specific PROs do NOT observe a linear relationship with the PASI score
–Reasons for dissatisfaction even when psoriasis is completely cleared include:

• residual itch (pruritus)
• skin pain
• stigmatization (psychological scar)
• arthritis

Conclusions
-Objective strong improvement of psoriasis differ between patients and doctors. An objective improvement as seen by doctors is not always viewed as such by patients.
–Even complete clearance of lesions can leave the patient dissatisfied.
-One explanation is an increase in patient’s expectations when the disease improves. For example: When there is flaring, the DLQI increases disproportionately as patients display a change in standard of what is tolerated. (study done by Abbvie)

Patient reported outcomes and the association with clinical response to anti-psoriatic treatments. Bruce Strober (United States). SY31 – Clinical Aspects of Psoriasis, Including Co-Morbidities. World Congress of Dermatology 2015 –  Vancouver, Canada