Public HealthTargetingNull

Camden Coalition Hotspotting RCT

MIT J-PAL North America / Camden Coalition of Healthcare Providers · Camden, New Jersey, USA · 2014

Summary

The Camden Coalition Hotspotting RCT is one of the most important null findings in recent US health policy. The intervention model — intensive multidisciplinary care management for high-utilizing patients — had been celebrated for nearly a decade before the trial was published, prominently featured in Atul Gawande's writing and widely cited as proof that targeted intervention could simultaneously improve patient outcomes and reduce healthcare spending. The randomized evaluation found neither effect. The 0.6-percentage-point difference in readmissions was statistically indistinguishable from zero, and the spending and ED outcomes were similarly unchanged. The result was uncomfortable to absorb because the intuitive theory had been compelling: identify the patients with the most preventable utilization, surround them with intensive support, save money and improve health. The empirical answer was that this particular implementation of that theory produced no measurable benefit. The underlying mechanism for the null is still debated — some argue 'regression to the mean' explains much of the apparent need (patients with extreme utilization in one period tend to revert toward average regardless of intervention), some argue the 90-day intervention window was too short, some argue the intervention's focus on care coordination missed the actual drivers of utilization in the population studied. What is clear is that the null finding has materially changed how subsequent super-utilizer programs are designed, evaluated, and funded.

Research question

"Does intensive care management for 'super-utilizers' — patients with very high rates of hospital admission and emergency department use — reduce subsequent readmissions and total healthcare utilization, as widely advocated by health-policy commentators?"

Methodology

Intervention

Patients identified as high-utilizers (multiple hospitalizations in the prior six months) were assigned to receive intensive care management from a multidisciplinary team of nurses, social workers, community health workers, and physicians for 90 days post-discharge. The team coordinated medical care, helped patients access benefits, addressed housing and food insecurity, and accompanied patients to follow-up appointments. The model — featured prominently in Atul Gawande's 2011 New Yorker article 'The Hot Spotters' — was widely viewed as a cost-saving exemplar before this evaluation.

Assignment

Randomized controlled trial — high-utilizer patients randomly assigned to the Camden Coalition's care-management intervention or to usual care

Sample size

800 patients randomly assigned (400 treatment, 400 control)

Primary outcome

Hospital readmission rate within 180 days post-discharge; secondary outcomes included total Medicaid spending, ED visits, and quality-of-life measures

Effect estimate

Readmission rate: 62.3% treatment vs. 61.7% control — a non-significant difference of 0.6 percentage points (95% CI: -7 to +8 pp). The intervention produced essentially no effect on the primary outcome. Total Medicaid spending and ED utilization were also unchanged.

Decision

Findings substantially reshaped the policy debate over 'hotspotting' approaches to healthcare cost containment. The Camden Coalition has continued operating but pivoted its model to focus on different patient populations and outcomes. The result has been cited in subsequent debates over CMS hospital readmissions policy and Medicare/Medicaid demonstration programs targeting super-utilizers, with most subsequent evaluations finding similar nulls.

View source report →

Result

Null

Evidence strength

Strong

Randomized controlled trial with large sample.

Replication status

Open for replication

Institution

MIT J-PAL North America / Camden Coalition of Healthcare Providers

Location

Camden, New Jersey, USA

Year

2014

Policy area

Public Health

Mechanism

Targeting

Cross-references

Adjacent experiments — same domain, parallel pilots, or alternative mechanisms.

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Open for replication

Could your jurisdiction test this?

This finding has not yet been independently replicated. A replication in a new context — a different city, country, or population — is one of the highest-value contributions to the evidence base. If your team could host a replication, we can help with study design, sample-size estimation, and analysis.

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