That's a key issue addressed by law prof Alexandra Lahav in Mass Tort Class Actions – Past, Present, and Future. Here is the abstract:
The judicial experiment with mass tort class actions was an anemic one, albeit somewhat spectacular in a few cases that have captured the academic and professional imagination. This Essay explains that the reason mass tort class actions never thrived is that there is a disconnect between tort doctrine on the one hand, and tort theories and procedures on the other. Tort doctrine has largely failed to accommodate social scientific developments in fields such as epidemiology. Tort theories such as risk-spreading and deterrence, as well as the procedural law, especially common-law like informal procedural ordering, have filled the breach. The future of the mass tort class action depends on tort doctrine’s ability to take risk, probability, [and] the possibilities of statistical proof into account.