Detailled Information

Name of the Instrument/Tool Patient global assessment (PGA)
First Description

Scott PJ, Huskisson EC. Measurement of functional capacity with visual analogue scales. Rheumatol Rehabil 1977;16:257–9.

Year 1977
Domains
Concept of constructs Global assessment
Population/Disease Generic
Originally developed for Rheumatoid Arthritis (RA)
Other rheumatic diseases
where can be applied (only if validated)
Gout, Psoriatic Arthritis (PsA), Low Back Pain (LBP), Osteoarthritis (OA), Systemic Lupus Erythematosus (SLE), Ankylosing spondylitis (AS), ANCA-associated vasculitis (AAV), Idiopathic Inflammatory Myopathies (IIM)
Additional population with no rheumatic diseases No
Language: Originally published in English
Available in Language English
REFERENCE IDENTIFICATION
Author/s Scott PJ, Huskisson EC
Title Measurement of functional capacity with visual analogue scales.
Journal Rheumatol Rehabil
Year 1977
Vol 16
Num ---
Pages 257–9.
Country UK
Language English
Other references of interest
Link http://www.ncbi.nlm.nih.gov/pubmed/18375533
Brief Description

Systematic literature review of 109 reports, (45% randomised controlled trials) assessing 63 questionnaires or tools for PROs corresponding to 14 domains of health. Frequently reported domains (and most frequent tools) were: function, 83% (most frequent tool, health assessment questionnaire, HAQ); patient global assessment, 61% (most frequent tool, visual analogue scale, VAS); pain, 56% (VAS); and morning stiffness 27%. This review revealed that PROs are reported with great heterogeneity in RA studies with some domains that are important from the patient’s perspective being infrequently reported.

Link http://www.ncbi.nlm.nih.gov/pubmed/22588741
Brief Description

A report of selected disease activity measurement instruments in rheumatoid arthritis based on expert panel recommendations for use in the clinical setting and for research. The report includes a description of the instruments along with practical application, a discussion of psychometric properties and a critical appraisal of their overall value to the rheumatology community.

Link http://www.ncbi.nlm.nih.gov/pubmed/23378146
Brief Description

This study assessed a self-administered questionnaire containing five versions of the 100 mm PG-VAS in 50 patients with RA on biologics. All PG-VAS versions correlated strongly with each other. However, individual scores for each PGA-VAS, had wide limits of agreement and the different phrasing resulted in different DAS28 results (largest difference in DAS28 scores = 0.63). The study highlighted the need for standardizing and validating the PGA. Since DAS28 is a key outcome measure and itself a major influence of clinical decisions relating to eligibility for biologic agents and evaluation of new therapies, such differences stemming from heterogeneity in the phrasing of the PGA need to be eliminated

Instrument/Tool Translations References
No other References.
DEVELOPER CONTACT INFORMATION
Correspondence to no formal development of this tool
E-Mail ---
Address ---
Website ---
Available ---
Links ---
DESCRIPTION OF THE INSTRUMENT
Type Of Measure VAS, NRS
Brief Description

The Patient Global Assessment is a one sentence numerical or visual rating scale which assesses global opinion. There exist different formulations and those can be adjusted for every disease. The difference lays in whether the global assessment uses the word 'global health' or 'disease activity'.

An example of phrasing of the global health version is:
"Considering all the ways in which [disease] may affect you at this time, please mark how you are doing"

An example of the phrasing as disease activity is:
"How active do you consider your [disease]?"

 

For more information, refer to Nikiphorou et al., AR&T 2016

Number of Items 1
Range 0-10 or 0-100
Responses options/scale Yes
none (no free text)
Developed for Both
PRACTICAL APPLICATION
Method of administration Online, Self-administered
Recommendations to score

If no numbered scale used, using a ruler, the distance in mm from the left border of the VAS to the point where the patient marked their response on the line, is measured. VAS consisting of circles can be scored by visual inspection without the need for a ruler.

Score Interpretation The level of disease activity increases with increasing score i.e. higher score implies worse disease activity.
Cut-off points Define: 0-100 mm or 0-10cm or very well – very poorly or inactive – very active. Values below 4/10 usually considered low/aceptable
Cut-off points applied to Both
Smallest detectable change if described 26.2 mm Reference link: Uhlig et al., Ann Rheum Dis 2009;68:972-975
Smallest detectable change applied to Not specified
Completion time by the patient <1 minutes
Scoring time by the assessor <1 minutes
Training to score Not necessary
Strengths Widely used, Easy to use, Useful in clinical practice & research
Limitations ---
OTHER COMMENTS
Other Comments

PGA is widely used, is part of DAS28 in rheumartoid arthritis and is available in many languages but other languages than English have not been published per se and thus are not made available here.

For further information on measurement properties, please refer to:

Nikiphorou E, et al. Patient global assessment in measuring disease activity in rheumatoid arthritis: a review of the literature. Arthritis Res Ther. 2016;18(1):251. Published 2016 Oct 28. doi:10.1186/s13075-016-1151-6