Are patient questionnaire scores as "scientific" as laboratory tests for rheumatology clinical care?

Modern medical care is based largely on laboratory advances, such as microbiological cultures giving rise to antibiotics and hemoglobin A1c leading to "tight control" of diabetes, among many others. Development of a "gold standard" laboratory test has appeared attractive for care of patients with rheumatoid arthritis (RA) since rheumatoid factor was identified in the 1940s. Indeed, rheumatoid factor, anti-cyclic citrullinated peptide (anti-CCP) antibodies, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) are abnormal in most RA patients. However, each of these tests is normal in at least 30% of patients, and no laboratory test (or any other measure) can serve as a single "gold standard" measure for all individual RA patients. A new approach to quantitative assessment in rheumatic diseases involves patient self-report questionnaires as standardized, quantitative, cost-effective "scientific" data from a medical history, the primary source of RA management decisions. Patient questionnaires distinguish active from control treatments in RA clinical trials at levels similar to laboratory tests (or formal joint counts), and are far more significant in the prognosis of work disability, costs, and premature death than laboratory tests or radiographic scores. RAPID3 (routine assessment of patient index data) on an MDHAQ (multidimensional health assessment questionnaire) requires 5 seconds to score, compared to 114 seconds for a DAS28 (disease activity score). Patient questionnaires do not replace further medical history, physical examination, laboratory or other tests, and require physician interpretation for patient management, as do laboratory tests and all quantitative data. Advances in therapy require laboratory science, but patient questionnaires provide optimal "scientific" data for clinical care.