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Effective Use of Census Registries in Multidistrict Litigation

Megan Lee Pizor


  • 28 U.S.C. § 1407 was enacted to manage litigation involving common questions of fact through MDL, which has seen a significant increase in the number of pending cases.
  • The Advisory Committee on Civil Rules has proposed Rule 16.1 of the Federal Rules of Civil Procedure to guide the management of MDLs, emphasizing early information exchange for efficient pretrial proceedings.
  • Census registries, a process for gathering data on filed and unfiled claims, are explored as a tool for early vetting in MDLs.
  • Best practices for using census registries in MDLs include considerations for data normalization, addressing challenges of "free text" fields, and the role of third-party aggregators.
Effective Use of Census Registries in Multidistrict Litigation
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In 1968, Congress enacted 28 U.S.C. § 1407 so that litigation spanning multiple districts and involving “one or more common questions of fact” could be better managed. The statute allowed for the consolidation of such litigation for the purposes of more efficient pretrial proceedings via “multidistrict litigation” (more commonly referred to as “MDL”). 28 U.S.C. § 1407(a). Since that time, the number of actively pending MDLs has increased exponentially, reaching one million pending cases in 2021. See Lawyers for Civil Justice (LCJ), “MDLs Reach 1 Million Case Milestone: LCJ Calls for Fresh Scrutiny of Rules for MDLs,” Rules4MDLs, Mar. 18, 2021. For years, there have been discussions and debates on the management of MDLs and how to most efficiently and effectively approach the many complex issues that arise with the increasingly large number of claims and plaintiffs involved. This article explores the importance of early vetting of claims, as well as the potential impact of using census registries in multidistrict litigation. 

Draft Rule 16.1 of the Federal Rules of Civil Procedure: What It Means for Litigation Attorneys

The Advisory Committee on Civil Rules has recently proposed a federal rule to specifically govern the management of MDLs. Proposed new Rule 16.1 of the Federal Rules of Civil Procedure is intended to provide guidance to courts and parties regarding early case management in MDLs. See Advisory Committee on Civil Rules Agenda Book, March 28, 2023. The draft rule emphasizes the importance of an early information exchange in legal proceedings, aiming to streamline the litigation process by encouraging parties to identify and address key issues as soon as possible. An early information exchange can include processes to verify claims for merit as outlined in proposed new Rule 16.1(c)(4):

Experience has shown that in certain MDL proceedings early exchange of information about the factual bases for claims and defenses can facilitate the efficient management of the MDL proceedings. Some courts have utilized “fact sheets” or a “census” as methods to take a survey of the claims and defenses presented, largely as a management method for planning and organizing the proceedings.

The level of detail called for by such methods should be carefully considered to meet the purpose to be served and avoid undue burdens. Whether early exchanges should occur may depend on several factors, including the types of cases before the court. For example, it is widely agreed that discovery from individual class members is often inappropriate in class actions; however, with regard to individual claims in MDL proceedings, the exchange of individual particulars may be warranted. The timing of these exchanges may depend on other factors, such as whether motions to dismiss or other early matters might render the effort needed to exchange information unwarranted. Other considerations might include whether there are legal issues that should be addressed (e.g., general causation or preemption) and the number of plaintiffs in the MDL proceeding. Id.

The draft rule outlines that the transferee court should schedule an initial management conference to develop a management plan for orderly pretrial activity in MDL proceedings. In addition, the rule encourages parties to submit a report to the transferee court prior to the initial MDL management conference addressing any matter designated by the court.

The deadline for public comment on the draft rule is February 16, 2024. The proposed rule is set to take effect on December 1, 2025; however, it can be delayed for various reasons or withdrawn entirely according to the United States Courts. See Administrative Office of the U.S. Courts, Pending Rules and Forms Amendments.

A work-in-progress version and commentary on the guidelines and best practices can be viewed and downloaded at the Rabiej Litigation Law Center. See Developing Mass-Tort MDL Initial-Management Conference Guidelines and Best Practices (Oct. 4, 2023).

Census Registry Basics in Multidistrict Litigation

A census registry is an initial census questionnaire developed by parties to meet the specific allegations and requirements of a particular matter. The data from the registry can be used to provide visibility into the claimant/plaintiff inventory, including jurisdictional, allegation, and other trends. These insights enable early vetting of claims, initial case assessments, and claim verification data.

In recent litigations, the key difference between an “MDL census” and an “MDL census registry” has primarily been driven by unfiled claimants as opposed to filed plaintiffs. In census registries, there is typically a process used to gather information on the inventory of unfiled claims in exchange for some form of benefit, such as tolling of the statute of limitations for a specified period.

MDL census. An MDL census is most frequently used as a tool implemented by judges and special masters to gather early and high-level data on the inventory of filed cases. The purpose is to gauge the extent of use or exposure and alleged injuries among plaintiffs and to appoint leadership positions.

MDL census registry. An MDL census registry is typically a process and supporting technology that allows unfiled claimants to “register” their claims prior to filing suit. This is frequently managed by a third-party vendor or claims administrator. The purpose is to gain insight into case inventory and potentially identify meritless or unsupported claims. Census registries may be limited to unfiled claimants only or may include both filed and unfiled claim information.

MDLs Using the Census Registry Process

The following four cases are examples of MDLs that have adopted the census registry process.

  • In re 3M Combat Arms Earplug Products Liability Litigation, MDL No. 2885

Pretrial Order (PTO) No. 18—Order Governing Initial Census Requirements for Filed Cases (Oct. 22, 2019)

  • In re Juul Labs, Inc. Marketing, Sales Practices & Products Liability Litigation, MDL No. 2913

Case Management Order No. 2—Initial Census (Nov. 19, 2019)

  • In re Zantac (Ranitidine) Products Liability Litigation, MDL No. 2924

PTO No. 15—Order on Procedures for Implementing Census (Apr. 2, 2020)

  • In re Philips Recalled CPAP, Bi-Level Pap, and Mechanical Ventilator Products Litigation, MDL No. 3014

PTO No. 25—Approving Census Registry Program (Sept. 14, 2022)

Census Registries and Plaintiff Fact Sheets Compared

Plaintiff fact sheets (PFSs) are typically longer in comparison with census registries. Many factors can contribute to the length of a PFS, such as the size and complexity of the case and the type or range of alleged injuries.

PFSs are a significant investment in both time and cost. Because PFSs are longer in nature, they require a much longer period of negotiation between parties, as well as time invested in setting up a technology tool that is aimed at discovery and will meet all the needs of all parties.

PFSs have traditionally been used in MDLs to collect information about individual plaintiffs. See Litigation Management, Inc., Making Fact Sheets, Discovery & Document Management Work for You in Litigation. As noted by a Lawyers for Civil Justice comment submitted on September 9, 2020, to the Advisory Committee on Civil Rules and its MDL Subcommittee, PFSs are not used early enough, acknowledging “the average time from Panel centralization to entry of a PFS order in the proceeding it studied was over 8 months.” See Comment submitted by LCJ to the Advisory Committee on Civil Rules and Its MDL Subcommittee (Sept. 9, 2020).

A census registry is typically a shorter, uniform set of questions for all claimants aimed at getting a high-level view of the claimant inventory and assessing if there are claims that do not meet specific exposure or usage criteria and should therefore be removed from the registry (and, presumably, prevented from future case filing).

Plaintiff Fact Sheets

  • Discovery tool
  • General information about plaintiffs and their claims
  • Filed plaintiffs only
  • Average length: 20–60 pages
  • Typically replaces the need for interrogatories or requests for production

Census Registries

  • Early vetting tool
  • Register claims prior to filing suit
  • Filed and unfiled claimants
  • Average length: 2–5 pages
  • Typically offers early vetting in exchange for tolling the applicable statute of limitation

Census registries serve as an expedited process to assess the claimant pool prior to filing suits. The following are data points to consider when determining if a census registry is appropriate for a litigation:

  • Number of potential claimants
  • Number of filed plaintiffs
  • Matter type
  • Number of defendants
  • Allegations/injuries

Best Practices when Using a Census Registry to Manage Early Vetting in MDLs

While the use of census forms and census registries is still relatively new, there is a great deal to be learned from the cases that have adopted this concept, including ways to continue fine-tuning the process for future litigations. The list below presents some of the lessons learned from Litigation Management, Inc.’s specific experience with census registries.

  • Data normalization and reporting. Ensuring proper data normalization (i.e., facilitating a cohesive, uniform set of questions and manner of data entry) allows for seamless data importing and processing. This leads to more accurate and comprehensive data analytics that can be sorted and filtered to best meet the needs of parties, judges, and special masters.
  • Challenges of “free text” fields. Free text fields do not allow for accurate analytics and reporting due the endless opportunity for errors and response ambiguity. For example, a free text field for plaintiffs to indicate state of residence may receive varying responses, such as OH or Ohio. The inadvertent inclusion of leading or trailing spaces can also complicate resulting analytics.
  • Defendant roles and obligations. In cases with multiple defendants and defendant types (such as chemical manufacturers, as well as distributors and other supply chain participants), it is important to come to a consensus as early as possible regarding the goals of the census registry—as well as expectations regarding resulting deliverables and analytics.
  • Regulatory or safety reporting. Unfiled claimants who are under tolling agreements may impact requirements for regulatory or product safety reporting. It can be very important to determine early on when and to what extent defendants will have access to aggregate claimant data, versus specific claimant data, in order to best plan for and meet individual regulatory obligations.
  • Addressing deficiencies. In any information-gathering tool (PFS, census registry, or other discovery medium), there will always be deficiencies, no matter how simple the form. A third-party vendor can provide ways to reduce the number and type of deficiencies, as well as tools to both prevent and quickly identify such deficiencies.
  • Tolling of unfiled claims. The tolling of unfiled claims can have benefits to both plaintiffs and defendants, including the ability to gather information earlier in the litigation than may be available through more traditional discovery tools (such as a PFS). However, there are also concerns about the impact of potentially encouraging a higher volume of potential litigants, due to the lower thresholds required for census registries compared with more thorough PFSs. Parties should fully consider the pros and cons of gathering information on unfiled claimants, the impact of tolling, and what tools or options may be used to mitigate risk and best manage early discovery—based on the unique needs of the specific matter.
  • Cost-sharing considerations. Both parties will need to assess the cost of implementing a census registry. The anticipated volume of claimants or plaintiffs is a key factor to consider when performing a cost-benefit analysis; higher volumes may increase the value of a census registry. Using an experienced third-party vendor can provide the option of cost sharing.
  • Role of third-party aggregators. Third-party aggregators may assist plaintiff firms with identifying claimants and performing initial case intake. The use of aggregators can sometimes affect the occurrence or frequency (or both) of duplicates and dual representations. For matters that may involve third-party aggregators or otherwise anticipate an increased potential for duplicates or dual representations, effective census registry platforms can help to identify and reduce the occurrence of duplicated claimant entries.


Litigation is unique. Every MDL requires different types and levels of management functions for the collection and mining of pretrial discovery data. These functions should be customized to fit the needs of the parties and the court within the specific litigation. The parties hold the power to design an effective and efficient data exchange process—which may require support from experts or experienced third parties. Complex litigation will continue to grow and evolve, as will the possibilities for enhanced data management tools—such as artificial intelligence. What remains to be seen are the potential changes and solutions judges, practitioners, and experts will bring to the ever-evolving task of managing mass tort MDLs if proposed new Rule 16.1 of the Federal Rules of Civil Procedure is implemented.