Population-Based Breast Cancer Screening in a Primary Care Network

The US healthcare system is dramatically expanding the use of health information technology as a way to improve the quality and efficiency of care.^1,2 In primary care networks, population- based surveillance is being used to identify specific individuals for prevention or disease management interventions. To date most interventions have focused on the use of electronic health records to facilitate care during office-based visits or inpatient hospital admissions.^3-5

A novel informatics system to facilitate population-based preventive cancer screening was developed and implemented within a large primary care network.⁶ Breast cancer screening was chosen because it is the most common cancer in women and the second-most-common cause of cancer-related death,⁷ because there is scientific evidence supporting screening to decrease breast cancer mortality,^8,9 and because many women are not being regularly screened despite broad consensus about the value of screening, especially for postmenopausal women.^10,11 The study’s goal was to increase breast cancer screening rates by identifying eligible women overdue for a mammogram and allowing primary care providers to use an informatics tool to quickly review overdue patients and initiate outreach for those selected for contact. The system then automatically mailed reminder letters to the selected patients, tracked mammogram ordering and completion, and facilitated the scheduling of reminder phone calls by practice delegates for women remaining unscreened.

Previous results demonstrate that among women overdue for screening at the start of the study period (prevalent cohort), this system increased breast cancer screening rates over 1 year of follow-up.¹² Outcomes for women who became overdue during the 1-year intervention period (incident cohort), representing those just becoming overdue after prior testing or newly eligible for screening based on age criteria, have not been previously reported. Because this incident cohort represents the ongoing population for reminder systems, the current report compares results in incident and prevalent cohorts and assesses the durability of the 1-time intervention benefit over a 3-year period.

METHODS

Study Design and Randomization

The informatics system used in this study, the controlled, cluster randomized trial method, and the primary outcome results over 1 year among individuals who were overdue for screening at the study start are described elsewhere.^6,12 A total of 12 primary care practices were allocated to intervention (n = 6) or usual care (n = 6) control groups after stratifying by practice type, the number of eligible patients, baseline mammography rates, and unaffiliated outside facility screening rates. Providers could not be blinded to group assignment. The study was approved by the institutional review board at Massachusetts General Hospital (MGH).

Setting and Participants

The study population consisted of 163,028 individuals seen in the Massachusetts General Primary Care Practice- Based Research Network during the 3 years ending December 31, 2006. All patients were linked to either a specific primary care physician (PCP) or (for patients who could not be linked to a specific physician) to the primary care practice where they received most of their care, using a previously validated algorithm.^13,14 This linking ensured that the review of women overdue for breast cancer screening was by the PCPs or practices most directly responsible for each patient’s care.

Eligible study subjects were women 42 to 69 years of age who had no record of mammography in the prior 2 years. This group included women who were overdue as of the intervention start date (March 20, 2007; prevalent cohort) or became overdue during the first year of follow-up (March 20, 2007-March 19, 2008; incident cohort). Patients were excluded if their listed PCP was outside of the MGH network, they had previously undergone bilateral mastectomy, or they had died. All practices used electronic health records that provided visit-based cancer screening reminders.

Study Intervention

The informatics tool was implemented in the 6 intervention practices on March 20, 2007, and remained available to providers through March 19, 2010. During the intervention year (through March 19, 2008), providers received reminders to use the tool. After this 1-year period, providers could still use the tool, but they received no additional reminders and the original patient registry was not updated. For intervention providers, the informatics tool consisted of a web page listing their eligible patients linked to the network’s electronic health record.

Physician and Population Manager Role. Separate list views were visible for PCPs for their own patients and for practice-designated population managers (nurses, medical assistants, or nonclinical staff) for patients in each practice not linked to a specific PCP. Physicians and population managers received 3 e-mail reminders (start date, 3 months, 8 months) with a direct link to the population screening web page during the intervention year. A mailed reminder with step-by-step instructions was sent to physicians not yet using the system after 2 months. The web page could also be accessed directly from the hospital’s intranet and included (1) a list of overdue patients, (2) clinically relevant decision support information to help determine whether or not to initiate patient contact, (3) an actionable component to initiate or defer the mammography screening process. If a provider initiated patient contact, a centralized process was started with a letter. Providers could also defer screening (eg, if the patient had previously declined screening after a discussion or had screening done elsewhere) and remove a patient from their list for the remainder of the study. Electronically signed patient letters were sent centrally and included information about the value of screening and how to schedule a mammogram.

Practice Delegate Role. Physicians and population managers were linked with a practice-specific delegate (nonclinical staff or medical assistant) who used his or her own version of the informatics tool to facilitate tracking and scheduling of patients needing contact. Practice delegates were responsible for contacting patients who did not schedule screening on their own. When speaking with patients, delegates could schedule a mammogram by directly accessing the hospital’s radiology ordering system using the informatics tool.

Outcome Assessment