Sharp Score and Sharp/van der Heijde Score

The Sharp Score is a means of evaluating joint damage in joints of the hands, including both erosion and joint space narrowing.¹⁷⁷ Although it has undergone modifications since its introduction, the version proposed in 1985 has become the standard approach. In this method, 17 joint areas in each hand are scored for erosions; 18 joint areas in each hand are scored for joint space narrowing. The score per single joint for erosions ranges from 0 to 5 and for joint space narrowing from 0 to 4. In both cases, a higher score is worse. Erosion scores range from 0 to 170 and joint space narrowing scores range from 0 to 144. Thus, the “total Sharp Score” is the sum of the erosion and joint space narrowing scores, or 0 to 314.

The Sharp/van der Heijde (SHS) method, introduced in 1989, overcame one drawback to the Sharp Score, namely its focus on only hands, given that feet can also be involved early in rheumatoid arthritis. Therefore, the SHS method was developed to take account of erosions and joint space narrowing in both hands and feet.^{178, 179} As with the Sharp Score, higher scores reflect worse damage. Erosion is assessed in 16 joints in each hand and 6 joints in each foot. Each joint is scored from 0 to 5 with a maximal erosion score of 160 in the hands and 120 in the feet. Joint space narrowing and subluxation are assessed in 15 joints in the hands and 6 joints in the feet. Each joint is scored from 0 to 4 with a maximal score of 120 in the hands and 48 in the feet. The erosion and joint space narrowing scores are combined to give a total SHS score with a maximum of 448 (weighted toward hands because more joints are scored).

Numerous variants on the Sharp or SHS scores have been developed, differing subtly in terms of the numbers of joints measured and other details.¹⁸⁰ Generally, all the Sharp methods are very detailed assessments and the approach, although reliable and sensitive to change, is considered time-consuming and tedious. For a speedier approach, Larsen and colleagues developed a simpler approach.

Larsen Scale for Grading Radiographs

The Larsen Scale is an overall measure of joint damage, originally devised in the 1970s and updated most recently in the late 1990s.^181–185 It produces both a score for each joint (hands and feet) and an overall score that reflects measurement and extent of joint damage. Scores range from 0 (“normal conditions,” i.e., intact bony outlines and normal joint space) to 5 (“mutilating abnormality,” i.e., original bony outlines have been destroyed), so higher scores reflect greater damage. Scores can range from 0 to 250.

Health Assessment Questionnaire

The Health Assessment Questionnaire (HAQ) is a widely used self-report measure of functional capacity; it is a dominant instrument in studies of patients with arthritis (particularly trials of drugs in patients with rheumatoid arthritis), but it is considered a generic (not disease-specific) instrument. The accepted minimally clinically important difference (MCID) for HAQDI in RA is a change of 0.22-0.25.¹⁶⁵ Other detailed information on its variations, scoring, etc., can be found at www.chcr.brown.edu/pcoc/EHAQDESCRSCORINGHAQ372.PDF (accessed for this purpose 10/3/2017) or www.hqlo.com/content/1/1/20 (accessed for this purpose 10/3/2017) and in the seminal reports by Fries et al.¹⁸⁶ and Ramey et al.¹⁸⁷

The full, five-dimension HAQ consists of four domains: disability, discomfort and pain, toxicity, and dollar costs, plus death (obtained through other sources). More commonly, “the HAQ” as used in the literature refers to the shorter version encompassing the HAQ Disability Index (HAQ-DI), the HAQ pain measure, and a global patient outcome measure. The HAQ-DI is sometimes used alone.

The HAQ-DI, with the past week as the time frame, focuses on whether the respondent “is able to…” do the activity and covers eight categories in 20 items: dressing and grooming, arising, eating, walking, hygiene, reach, grip, and common daily activities. The four responses for the HAQ-DI questions are graded as follows: without any difficulty = 0; with some difficulty = 1; with much difficulty = 2; and unable to do = 3. The highest score for any component question in a category determines the category score. The HAQ-DI also asks about the use of aids and devices to help with various usual activities. Two composite scores can be calculated, one with and one without the aids/devices element; both range from 0 to 3.

The HAQ pain domain is measured on a doubly-anchored horizontal visual analog scale (VAS) of 15 cm in length; one end is labeled “no pain” (score of 0) and the other is labeled “very severe pain” (score of 100). Patients mark a spot on the VAS, and scores are calculated as the length from “no pain” in centimeters (cm) multiplied by 0.2 to yield a value that can range between 0 and 3.

With respect to interpretation, HAQ-DI scores of 0 to 1 are generally considered to represent mild to moderate disability, 1 to 2 moderate to severe disability, and 2 to 3 severe to very severe disability.

The HAQ global health status scale measures quality of life (essentially, as how the patient is feeling) with a 15 cm doubly-anchored horizontal VAS scored from 0 (very well) to 100 (very poor).

Medical Outcomes Study Short Form 36 Health Survey

The Medical Outcomes Study Short Form 36 Health Survey (SF-36) is an internationally known generic health survey instrument. Information can be found at https://www.rand.org/health/surveys_tools/mos/36-item-short-form.html (accessed for this purpose 10/3/2017) and in a large number of articles documenting its psychometric properties.^188–194 It comprises 36 items in eight independent domains tapping functioning and well-being: physical functioning, role-physical, bodily pain, and general health in one grouping (physical health) and vitality, role-emotional, social functioning, and mental health in another grouping (mental health). The SF-36 provides a separate scale score for each domain (yielding a profile of health) and two summary scores, one for physical health and one for mental health. Each scale is scored from 0 to 100 where higher scores indicate better health and well-being. The accepted MCIDs for the SF-36 physical component score in RA is 4.4, and for the SF-36 mental component score, it is 3.1.^{166, 167}

A “version 2” of the SF-36 was introduced in the late 1990s to correct some drawbacks in formatting, wording, and other issues and to update the norm-based scoring with 1998 data. It can be fielded in two versions varying by recall period: 4-week recall (the usual approach) and 1-week recall (acute). More recently, it has been tested and used for computer adaptive testing according to item response theory principles.

EuroQol EQ-5D Quality of Life Questionnaire

A third generic quality-of-life instrument is the EuroQol EQ-5D Quality of Life Questionnaire, typically known just as the EQ-5D. More information can be found at http://www.euroqol.org/ (accessed for this purpose 10/3/2017) and in key descriptive articles,¹⁹⁵ one of which is about patients with rheumatoid arthritis.¹⁹⁶

The EQ-5D covers health status in five domains (three questions each): mobility, self-care, usual activities, pain or discomfort, and anxiety or depression. It is intended for self-response but can be used in other administration modes. Each item can take one of three response levels – no problems, some moderate problems, extreme problems – identified as level 1, 2, or 3, respectively. This yields a profile of one level for each of the five domains; this is essentially a five-digit number, and no arithmetic properties attach to these values. Users can convert health states in the five-dimensional descriptive system into a weighted health state index by applying scores from EQ-5D “value sets” elicited from general population samples to the profile pattern (e.g., 1, 2, 3, 3, 1).

The EQ-5D also has a global health VAS scale (20 cm) scored from 0 to 100.

American College of Rheumatology 20/50/70

The American College of Rheumatology (ACR) criteria are concerned with improvement in counts of tender and swollen joints and several domains of health.¹⁹⁷ A principal aim of these criteria is use in studies (particularly trials) of drugs for rheumatoid arthritis. More information can be found at https://www.rheumatology.org/Portals/0/Files/ACR%20Preliminary%20Definition%20Of%20Improvement%20In%20Rheumatoid%20Arthritis_Manuscript.pdf and https://www.hopkinsarthritis.org/physician-corner/education/arthritis-education-diagnostic-guidelines/#ra_trials (both accessed for this purpose 10/3/2017). Originally these latter involved patient assessment, physician assessment, erythrocyte sedimentation rate, pain scale, and functional questionnaire.

Today, based on work done in the mid-1990s,¹⁹⁸ values for clinical trial patients are defined as improvement in both tender and swollen joint counts and in three of the following: patient’s assessment of pain; patient’s global assessment of disease activity, patient’s assessment of physical function (sometimes referred to as physical disability), the physician’s global assessment of disease activity, and acute phase reactant (C-reactive protein, or CRP). The 20, 50, or 70 designations (sometimes called the ACR Success Criteria) refer to improvements in percentage terms to 20 percent, 50 percent, or 70 percent in the relevant dimensions. A physician’s global assessment of 70 percent improvement is considered remission.

Thus, patients are said to meet ACR 20 criteria when they have at least 20 percent reductions in tender and swollen joint counts and in at least three of the domains. ACR50 and ACR70 criteria are defined in a manner similar to that for ACR 20, but with improvement of at least 50 percent and 70 percent in the individual measures, respectively. The table illustrates, in a study context, how a patient might be said to have an ACR50 response.

EULAR Response Criteria

The European League Against Rheumatism (EULAR) response criteria classify patients as good, moderate, or non-responders based on both change in disease activity and current disease activity, using either the DAS or the DAS28 (see description above).¹⁹⁹ For example, to be classified as a good responder a patient must have relevant change in DAS (≥1.2) and low current disease activity (≤2.4), while a non-responder must have ≤0.6 change in DAS and high disease activity (>3.7).²⁰⁰

The EULAR criteria have been validated in multiple clinical trials, and confirmed in an analysis of nine clinical trials that concluded a high level of agreement and equal validity between ACR and EULAR improvement classifications.²⁰¹ Good and moderate responders showed significantly more improvement in functional capacity and significantly less progression of joint damage than patients classified as non-responders.²⁰¹

Disease Activity Score

The Disease Activity Score (DAS) is an index of disease activity first developed in the mid 1980s. The history of its development and current definitions, scoring systems, and other details can be found at https://www.das-score.nl/das28/en/ (accessed for this purpose 10/3/2017) and in recent articles.^{179, 202} The DAS originally included the Ritchie Articular Index (see below), the 44 swollen joint count, the erythrocyte sedimentation rate, and a general health assessment on a VAS. Scores on the DAS can range from 1 to 9. A cut-off level of the DAS of 1.6 is equivalent with being in remission.

More recently, an index of RA disease activity using only 28 joints – the DAS28 – has been developed, focusing on joint counts for both tenderness (TJC) and swelling (SJC). It also uses either the patient’s or a physician’s global assessment (PGA) of disease activity (on a 100 mm VAS) and the erythrocyte sedimentation rate (ESR) or C-reactive protein. The formula for calculating a DAS28 score is as follows: = (0.56 × TJC^1/2) + (0.28 × SJC^1/2) + (0.7 × ln [ESR]) + (0.014 × PGA [in mm]). Numerous formulas to calculate a variety of DAS and DAS28 scores exist (see the website above), such as when a global patient assessment of health is unavailable.

The DAS28 yields a score on a scale ranging from 0 to 10. A DAS28 of 2.6 is considered to correspond to remission; a DAS28 of 3.2 is a threshold for low disease activity; and a DAS28 of more than 5.1 is considered high disease activity.

Ritchie Articular Index

This is a long-standing approach to doing a graded assessment of the tenderness of 26 joint regions, based on summation of joint responses after applying firm digital pressure.²⁰³ Four grades can be used: 0, patient reported no tenderness; +1, patient complained of pain; +2, patient complained of pain and winced; and +3, patient complained of pain, winced, and withdrew. Thus, the index ranges from 0 to 3 for individual measures and 0 to 78 overall, with higher scores being worse tenderness.

Certain joints are treated as a single unit, such as the metacarpal-phalangeal and proximal interphalangeal joints of each hand and the metatarsal-phalangeal joints of each foot. For example, the maximum score for the five metacarpal-phalangeal joints of the right hand would be 3, not 15. No weights are used for different types of joints (e.g., by size), because the issue is one of measuring changes (improvements) in tenderness; this is especially relevant for rheumatoid arthritis.