data are not yet available. Analogous systems are not clearly predictive of how they would function, and much depends on the choices made about system design. However, based on theoretical predictions and the limited evidence available, they likely merit further experimentation in the U.S. Exhibit 1 below summarizes the evidence reviewed in this report concerning the effects of the various reforms. Where conclusions can be drawn, the table includes an impressionistic rating of the strength of evidence available, considering the quantity and quality of research studies: high (H), medium (M), or low (L). When a reform’s effect on a particular outcome measure has not been studied, if there is a plausible, substantial theoretical) Defensive medicine and healthcare spending (could decrease) 4 Outcome Measures and Overall Strength of Evidence Other Plausible Relationships for Which Little or No Evidence is Available Certificate of merit laws Evidence sufficient for conclusions to be drawn: • None Evidence too mixed for conclusions to be drawn: • None • Claim frequency (could decrease) • Time to compensation (could increase) • Litigation costs (could increase for plaintiffs and decrease for defense) Attorney fee limits Evidence sufficient for conclusions to be drawn: • No change in claims frequency (M) • No change in compensation amounts (H) • No change in liability insurance premiums (M) • No change in physician supply (M) Evidence too mixed for conclusions to be drawn: • None • Litigation costs (could increase on average if attorneys are less inclined to bring small cases) • Differential impact on Medicare patients (could disproportionately burden patients with low damages) Joint-and-several liability reform Evidence sufficient for conclusions to be drawn: • No change in compensation amounts (M) • No change in liability insurance premiums (M) • No change in physician supply (H) • No change in quality of care (H) Evidence too mixed for conclusions to be drawn: • Defensive medicine and healthcare spending • Litigation costs • Health insurance coverage rates/costs • Access to compensation (could reduce plaintiffs’ ability to recover compensation) 5 Outcome Measures and Overall Strength of Evidence Other Plausible Relationships for Which Little or No Evidence is Available Collateral-source rule reform Evidence sufficient for conclusions to be drawn: • No change in claims frequency (M) • No change in compensation amounts (H) • No change in liability insurance premiums (M) • No change in defensive medicine/healthcare spending (M) • No change in physician supply (H) • No change in health insurance coverage rates (L) • No change in quality of care (H) Evidence too mixed for conclusions to be drawn: • None • Differential impact on Medicare patients (reducing liability awards could disproportionately burden elderly claimants) Periodic payment Evidence sufficient for conclusions to be drawn: • No change in claims frequency (M) • No change in compensation amounts (M) • No change in physician supply (M) • No change in patient care outcomes (L) Evidence too mixed for conclusions to be drawn: • Liability insurance premiums • Defensive medicine/healthcare spending • Insurers’ overhead costs (could increase or decrease) • Differential impact on some Medicare patients (persons with short lifespans and/or low savings may prefer a lump-sum payment) Shorter statute of limitations/repose Evidence sufficient for conclusions to be drawn: • No change in compensation amounts (M) • Reduction in growth of liability insurance premium costs (M) Evidence too mixed for conclusions to be drawn: • Claims frequency • Time to compensation (short statutes of limitation/repose could unduly bar valid claims) • Insurers’ overhead costs (could decrease) 6 Outcome Measures and Overall Strength of Evidence Other Plausible Relationships for Which Little or No Evidence is Available Innovative Reforms Health courts: Medical courts model Evidence sufficient for conclusions to be drawn: • None Evidence too mixed for conclusions to be drawn: • None • Claims frequency (could increase or decrease) • Number of claims paid (could increase or decrease) • Defensive medicine and healthcare spending (could decrease) Health courts: Administrative model Evidence sufficient for conclusions to be drawn: • Lower overhead costs (M) Evidence too mixed for conclusions to be drawn: • None • Claims frequency (could increase, if claimants perceive easier access to compensation) • Number of claims paid (could increase, if broader compensation standard used) • Compensation amounts (could decrease) • Provider liability costs (could increase or decrease) • Defensive medicine and healthcare spending (could decrease) • Quality of care (could improve) Communication and resolution programs (CRPs) Evidence sufficient for conclusions to be drawn: • Substantial reduction in claims frequency (L) • Reduction in claims payments (L) • Reduction in time to compensation/resolution (L) • Reduction in litigation costs (for patients and providers) (L) • Reduction in liability premiums (L) Evidence too mixed for conclusions to be drawn: • None • Defensive medicine and healthcare spending (could decrease, if providers perceive CRPs as protecting them). • Quality of care (could improve) 7 Outcome Measures and Overall Strength of Evidence