Rheumatology – Don’t Trust the Evidence Pyramid | Figure 1

msputman

Rheumatology

Rheumatology – Don’t Trust the Evidence Pyramid

Today I wanted to focus the newsletter on a meme that I have frequently seen rheumatologists share; the so-called “evidence pyramid.” This pyramid ( pictured above) ostensibly describes a “hierarchy” of evidence to help guide clinicians in critical appraisal. The bottom of the pyramid typically includes case reports and expert opinion, followed by observational data of some variety, randomized trials (RCTs), and then — at the very pinnacle of “evidence” — the systematic review +/- meta-analysis (SRMA). This looks pretty and feels reasonable, but today I want to convince you to never share it again.

SRM-No-Way

First and foremost, systematic reviews and meta analyses (SRMAs) are emphatically not the highest level of evidence. I would argue that they themselves are not evidence at all, but rather a lens through which we view actual evidence from RCTs and observational studies. They depend upon the quality of the review process (many are very low quality) and the evidence that they appraise (often small studies with various methodologies). Moreover, because there is a “ mass production of redundant, misleading, and conflicted systematic review and meta-analyses,” the chances that a given meta-analysis represents a true finding is likely less than 50%. In fact, under current assumptions a famous paper by J.P. Ioannidis (over 10,00 citations since 2005!) suggests this to be case.

References

Case Studies

A 52-year-old man

A 52-year-old man presented with a 20-minute history of chest pain radiating to the left shoulder and neck, associated with dyspnea and diaphoresis. He had a history of hypertension, long-term smoking, and a sedentary lifestyle. On physical examination, bibasilar crackles were noted on lung auscultation. An electrocardiogram (ECG) was performed in the primary care setting, and the patient was promptly referred to the emergency department.

A 28-year-old woman

A 28-year-old woman presented with a 3-day history of intense pruritus over the lower back. She reported no recent travel or exposure to new environments. She cares for a small kennel with approximately eight dogs rescued from the streets. Physical examination revealed multiple small vesicles, some clustered and others scattered, predominantly involving the lumbar region and the left gluteal area.

A 4-month-old male infant

A 4-month-old male infant presented with skin lesions localized to the chin for the past 3 days. Physical examination revealed multiple small pustules with surrounding inflammatory signs on the chin, along with a few scattered papules on the chest.

Patient in late teens

Patient in late teens presenting after a collapse, no chest pain, no previous cardiac history, no history of sudden death in family, are there any features in this EKG that would warrant further work-up or is this just a pediatric EKG?