Greatest Risk Factor for Medical Malpractice Claims
Among the options provided, cumulative patient volume is the greatest risk factor for being named in a medical malpractice claim.
Primary Evidence
The most direct evidence addressing this question comes from a 2018 study in Annals of Emergency Medicine that specifically examined risk factors for malpractice claims among emergency physicians 1. This analysis of over 9.4 million ED visits involving 1,029 physicians found that higher visit volume was independently associated with being named in a malpractice claim (adjusted odds ratio 1.09 per 1,000 visits; 95% CI 1.05 to 1.12) 1.
Why Patient Volume Matters Most
Direct exposure relationship: Each additional 1,000 patients treated increased the odds of being named in a claim by 9%, demonstrating a clear dose-response relationship between patient volume and litigation risk 1.
Years in practice (which correlates with cumulative volume) was the only other significant factor identified, with an adjusted odds ratio of 1.04 per year (95% CI 1.02 to 1.06) 1.
What Does NOT Increase Risk
The same high-quality study specifically examined and found no association between malpractice claims and:
- Hospital admission rate: Not associated with being named in claims 1
- Relative value units per hour: Not associated with malpractice risk 1
- Patient satisfaction scores: Initially showed no significant association in the primary analysis 1
Important Nuance on Patient Satisfaction
While the 2018 study found no association between patient satisfaction and being named in claims 1, there is conflicting evidence:
A 2009 study suggested that minimum satisfaction scores (the lowest score on any question) may predict malpractice risk at the departmental level, though it explained little variation at the individual physician level 2.
Interestingly, a 2020 study found that patient satisfaction scores actually improved after physicians were named in claims, suggesting satisfaction may be a consequence rather than a predictor of litigation 3.
Clinical Context
The fundamental principle is straightforward: more patient encounters = more opportunities for adverse outcomes = higher litigation exposure 1. This is a mathematical reality of medical practice rather than a reflection of quality of care. Even excellent physicians face increased risk simply by treating more patients over time.
Common Pitfall to Avoid
Do not confuse correlation with causation regarding admission rates or RVUs. While these might seem like proxies for aggressive or defensive practice patterns, the evidence shows they do not independently predict malpractice risk when controlling for patient volume 1.