On this page
- How is patient leakage different from referral leakage?
- What should you decide before measuring?
- How do you calculate network leakage?
- What does each data source show?
- How do you separate avoidable from payer-directed outflow?
- How do MSOs and PE-backed groups use it?
- What are the common mistakes?
- How do you set up a first measurement?
- How often should leaders review it?
- How Nuvory helps
Key takeaways
- Network leakage, also called patient leakage, is care for services your organization offers that patients receive from outside providers.
- Measure it as outflow share by service line, with a written definition of whose patients count and which services you offer.
- Your own EHR shows part of the picture; claims or HIE data shows outflow you never heard about.
- Split payer-directed and service-not-offered care from avoidable outflow before drawing conclusions.
- It is a leadership view for capacity and referral decisions, not a call list.
Network leakage is care for services your organization offers that patients receive from outside providers. It overlaps with referral leakage when the patient was referred to you. It is also called patient leakage, outmigration or outflow. For multi-site groups, MSOs, PE-backed platforms and health systems it is a strategic measure: it shows where capacity, access or referral relationships send patients elsewhere. Measuring it well takes three decisions before any formula: whose patients count, which services you offer, and which data sources you trust for care that happened outside.
How is patient leakage different from referral leakage?
Referral leakage is a referred patient who never completes the care they were referred for: never scheduled, scheduled and lost, or seen by another organization. It is covered in what is referral leakage. Network leakage looks at where care happens: services your organization offers that patients receive from outside providers, whether you referred them out, they chose another provider, or a payer directed them. The two overlap when the patient was referred to you. A practice that is slow to schedule inbound referrals often sees those patients turn up later as outflow.
What should you decide before measuring?
- Which patients count. Define the population, such as patients with a visit in the last 12 or 24 months, or patients attributed to your providers under a payer contract. Different definitions give different answers, so write yours down.
- Which services you offer. List the service lines and locations in scope. Outflow for a service you do not offer is a planning signal, not leakage.
- The unit. Count services, patients or episodes, and use the same unit in every period.
- The time period and lag. Outside data often arrives late. Claims in particular can take weeks or months to appear, so recent months will look better than they are until the data catches up.
How do you calculate network leakage?
Use a small set of formulas, by service line:
- Outflow share = services your patients received from outside providers ÷ all services of that type your patients received.
- Retention rate = 1 − outflow share.
- Avoidable outflow share = outside services excluding payer-directed care and services you do not offer ÷ all services of that type your patients received.
- Outbound referral share = referrals your providers sent outside for services you offer ÷ all referrals your providers made for those services.
Illustrative example. The numbers are round and hypothetical, not benchmarks. A group's patients received 1,000 imaging studies in a year. Claims show 300 were performed by outside facilities, so outflow share is 300 ÷ 1,000. Of the 300, 100 were payer-directed and 50 were a modality the group does not offer, leaving 150 potentially avoidable, or 150 ÷ 1,000 of all studies. If 90 of those 150 trace back to outbound orders from the group's own providers, the conversation starts with ordering habits and access, not marketing.
What does each data source show?
| Data source | What it shows | What it misses |
|---|---|---|
| Outbound orders and referrals in your EHR | Care your providers sent outside, and where | Care patients sought on their own |
| Staff closures recorded as completed elsewhere | Outside care your team learned about while working open orders or recalls | Anything nobody asked about |
| Payer claims | Services billed by other providers for your patients | Patients whose payer data you do not receive; recent months, because of lag |
| HIE notifications | Encounters at other facilities in the region | Facilities outside the HIE; detail about the service |
| Patient report | Why the patient went elsewhere | Completeness; it depends on someone asking |
Your own data is a partial view: it shows outflow your organization caused or heard about. Claims or HIE data shows the rest, such as imaging done at a competitor because it had an earlier slot.
How do you separate avoidable from payer-directed outflow?
Not all outflow is avoidable, and leaders lose trust in the number when it includes care they could never have kept.
| Reason | Avoidable? |
|---|---|
| Payer-directed site of care | Usually not |
| Service not offered | Not today, but a planning signal |
| Access: earlier appointment elsewhere | Yes |
| Patient preference or location | Sometimes |
| Referral sent out by habit | Yes |
Report payer-directed care and services not offered on their own lines, so leaders do not chase outflow they cannot change. Where the reason is unknown, say so rather than guessing.
How do MSOs and PE-backed groups use it?
For an MSO or a PE-backed platform, network leakage is a way to compare practices on the same terms and to find growth inside the existing patient base. Both depend on shared definitions first; see MSO revenue leakage definitions and measuring revenue leakage in PE-backed practices. Typical uses:
- Capacity planning. High avoidable outflow for one service line at one site often points to access: too few slots, long waits or limited hours.
- Referral relationships. Outbound referral share by provider shows where patients are sent outside by habit when the service exists in-house.
- Service-line decisions. Consistent outflow for a service the group does not offer is evidence for adding it.
- Consistency after acquisitions. Practices on different EHRs need the same patient definition, service list and reason codes before their numbers can be compared.
What are the common mistakes?
- Counting services you do not offer as leakage. It inflates the number and sends the conversation in the wrong direction.
- Changing the patient definition between periods. Trends then reflect the definition, not the patients.
- Reading recent months too early. Claims lag makes the latest period look better than it is.
- Using it as a call list. The care has already happened. Patients with open orders or recalls belong in the operational queues, not in a network report.
How do you set up a first measurement?
- Pick two or three service lines you offer at more than one site.
- Write the definitions: patient population, services in scope, unit and time period.
- Pull your own data first: outbound orders and referrals, and closures recorded as completed elsewhere. This gives a floor, not the full number.
- Add claims or HIE data where you have it, and note which payers or facilities are missing.
- Code a reason for each outside service where you can, using the table above, and leave unknowns as unknown.
- Review with the service-line leader before sharing the figure more widely. They will spot definition problems quickly.
How often should leaders review it?
Monthly or quarterly is typical, depending on how quickly outside data arrives. Review it by service line and site alongside capacity and wait-time measures, since those explain most avoidable outflow.
How Nuvory helps
Nuvory's network leakage software traces orders and referrals to where care was completed, counts closures recorded as completed elsewhere and adds claims or HIE data when connected. It is a leadership view on the Enterprise plan, not a call list. For the related inbound problem, see closed-loop referral management.
Frequently asked questions
Is network leakage the same as referral leakage?
Not quite; they overlap. Network leakage is care for services your organization offers that patients receive from outside providers. It overlaps with referral leakage when the patient was referred to you. Referral leakage also includes referred patients who are never scheduled or are lost before a visit, wherever they end up.
Can we measure network leakage without claims data?
Partly. Outbound orders, referrals and closures recorded as completed elsewhere show some of it. Claims or HIE data is needed to see outflow your organization never heard about.
Should we call patients who went elsewhere?
Generally no. The care has happened. Use the data to fix access, capacity and referral patterns. Patients with open orders or overdue recalls belong in operational work queues instead.
Which service lines should we measure first?
Start with service lines you offer at more than one site and that have clear outside alternatives, such as imaging or common procedures. They give the most useful comparisons and the clearest decisions about capacity and referral patterns.