Provider Patient-Sharing Networks and Multiple-Provider Prescribing of Benzodiazepines

Abstract

Background: Prescription benzodiazepine overdose continues to cause significant morbidity and mortality in the US. Multiple-provider prescribing, due to either fragmented care or "doctor-shopping," contributes to the problem.

Objective: To elucidate the effect of provider professional relationships on multiple-provider prescribing of benzodiazepines, using social network analytics.

Design: A retrospective analysis of commercial healthcare claims spanning the years 2008 through 2011. Provider patient-sharing networks were modelled using social network analytics. Care team cohesion was measured using care density, defined as the ratio between the total number of patients shared by provider pairs within a patient's care team and the total number of provider pairs in the care team. Relationships within provider pairs were further quantified using a range of network metrics, including the number and proportion of patients or collaborators shared.

Main measures: The relationship between patient-sharing network metrics and the likelihood of multiple prescribing of benzodiazepines.

Participants: Patients between the ages of 18 and 64 years who received two or more benzodiazepine prescriptions from multiple providers, with overlapping coverage of more than 14 days.

Results: A total of 5659 patients and 1448 provider pairs were included in our study. Among these, 1028 patients (18.2 %) received multiple prescriptions of benzodiazepines, involving 445 provider pairs (30.7 %). Patients whose providers rarely shared patients had a higher risk of being prescribed overlapping benzodiazepines; the median care density was 8.1 for patients who were prescribed overlapping benzodiazepines and 10.1 for those who were not (p < 0.0001). Provider pairs who shared a greater number of patients and collaborators were less likely to co-prescribe overlapping benzodiazepines.

Conclusions: Our findings demonstrate the importance of care team cohesion in addressing multiple-provider prescribing of controlled substances. Furthermore, we illustrate the potential of the provider network as a surveillance tool to detect and prevent adverse events that could arise due to fragmentation of care.

Keywords: drug overdose; prescribing patterns; social networks.

Fig. 1

Example of patient-sharing network. In this example, the care team for patient P1 consists of three providers (A1, A2, A3), and each provider pair has one shared patient (P1). Care density is defined as the ratio between the total number of patients shared by provider pairs in a care team and the total number of provider pairs in the care team. The care density for patient P1 is calculated as (X₁₂ + X₂₃ + X₁₃)/3, which equates to 1. To measure the relationship between providers A1 and A2, we examine the number of patients they share and the number of providers with whom they collaborate. Provider A1 has one patient (P1), and provider A2 has two patients (P1, P2). There is one shared patient between them (P1), and the proportion of shared patients is 1/2. Provider A1 has two collaborators (A2, A3) and provider A2 has four collaborators (A1, A3, A4, A5). The provider pair A1/A2 has a total of three collaborators, and only one shared collaborator (A3). Jaccard similarity is defined as the ratio between the intersection and union of shared provider. In this example, the Jaccard similarity of provider pair A1/A2 is 1/3.

Fig. 2

Study participant selection criteria

Fig. 3

Distribution of care density, comparing patients who received overlapping benzodiazepines and those who did not. The relationship between care density and multiple prescribing of benzodiazepines is non-linear.