Abstract
Introduction: Cystic fibrosis transmembrane conductance regulator (CFTR) modulators have revolutionized care for people with cystic fibrosis (pwCF) by improving quality of life and extending life spans. These factors support the need for pwCF to establish care with a Primary Care Provider (PCP). It is currently unclear how many adult pwCF routinely interact with a PCP.
Methods: This IRB approved, retrospective study included patients over 18 years old, seen in the adult Cystic fibrosis (CF) clinic, who were prescribed elexacaftor/tezacaftor/ivacaftor (ETI) between 8/31/2022 and 8/31/2023 at University of Iowa Health Care. The primary outcome of the study was to determine the percentage of pwCF with a PCP designated as a member of their care team in the electronic medical record (EMR). The secondary outcomes determined the percentage of pwCF who completed preventative health screenings for comorbid conditions and received appropriate cancer screenings and immunizations.
Results: Of the 115 included patients, 60% (69/115) had a PCP identified in the EMR. PwCF have uncontrolled blood pressure regardless of whether they have a PCP identified in the EMR (76.5%) or not (78.3%). Rates of influenza (p=0.006) and pneumococcal (p=0.006) vaccinations were significantly lower for pwCF without a PCP.
Discussion: There is a gap in healthcare for pwCF, especially for those who do not routinely interact with a PCP. CF clinicians may not be up to date on primary care management and PCPs may not be comfortable with treating patients with a high acuity chronic condition. PCPs should be better integrated into the CF care team to ensure pwCF are receiving comprehensive care.
- Care Coordination
- Chronic Disease
- Continuity of Care
- Cystic Fibrosis
- Multidisciplinary Care Team
- Patient Care Team
- Preventive Medicine
- Primary Health Care
- Pulmonary Medicine
- Screening
Introduction
Cystic fibrosis (CF) is a genetic disorder affecting approximately 40,000 individuals in the United States.1 It results from variations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein, an ion channel that regulates water and salt balance throughout many organs (e.g., lungs, pancreas, digestive tract).2 CFTR protein dysfunction impairs chloride and water transport, which increases mucus viscosity, leading to impaired mucociliary clearance, bronchiectasis, CF-related diabetes (CFRD), pancreatic insufficiency, and CF-related liver disease (CFLD).2,3
Since 2012, five CFTR modulators have been approved as treatment options for people with CF (pwCF), significantly improving quality of life, reducing CF symptoms, and extending life spans due to their unique mechanism of correcting and potentiating the altered CFTR protein.2–4 Elexacaftor/tezacaftor/ivacaftor (ETI) is classified as highly effective modulator therapy (HEMT) and can treat approximately 90% of variants expressed by pwCF in the United States.2 Following ETI’s FDA approval in 2019, the median predicted survival for pwCF increased from 45 years (2014-2018) to 61 years (2019-2023).4
Longer life expectancy increases the need to manage primary care conditions (e.g., diabetes, hypertension, obesity, etc.) and ensure appropriate screenings and vaccinations.5,6 While this continues to be an area of research, it is important to acknowledge that screening recommendations may vary due to a diagnosis of CF (e.g., pwCF require earlier colorectal cancer screening due to a 5-10 times greater risk of colorectal cancer).7
Current guidelines recommend pwCF visit an accredited CF care center every 3-6 months.8 Historically, many pwCF have not established with a primary care provider (PCP) due to shorter life expectancy and frequent specialty care visits. Additionally, PCPs may feel uncomfortable providing care to a patient with a complex chronic condition.5,6 While having a PCP is recommended, it remains unclear how many adult CF patients routinely interact with one. This question is strengthened by new guidance from the CF Foundation appointing PCPs as essential partners of the CF care team.8 A study by Haywood et al.6 found that 59% of adult CF patients in their program either identified the pulmonologist on their CF care team as the PCP or did not identify a PCP in their electronic medical record (EMR). The EMR corresponded with poor documentation of non-CF related screenings. This work aims to assess if pwCF identify a PCP and receive appropriate health screenings and preventative care.
Methods
This retrospective chart review included pwCF who were at least 18 years old, completed at least one visit in the adult CF clinic, and were prescribed ETI between 8/31/2022 and 8/31/2023 at University of Iowa Health Care. Exclusion criteria: history of a lung transplant (as this would introduce care by another multidisciplinary team) and lack of an office visit during the study period.
Centers for Disease Control and Prevention (CDC) recommendations were used to assess body mass index (BMI) and immunization status.9–14 Blood pressure (BP) control and lipid screening followed American Heart Association (AHA) and American College of Cardiology (ACC) guidelines.15,16 Osteoporosis screening aligned with the CF Clinical Care Guideline.17 Colonoscopy and mammogram recommendations followed the CF Colorectal Cancer Screening Task Force and American Cancer Society, respectively.7,18
The primary outcome of this study was to determine the proportion of pwCF with a PCP designated as a member of their care team in the EMR. Secondary outcomes included the proportion of pwCF who completed preventative health screenings for comorbid conditions and received appropriate cancer screenings and immunizations. This study was approved by the University of Iowa Institutional Review Board. Descriptive statistics were used for analysis. P values were calculated using Chi-square and Fisher Exact Test for subgroups less than five, with odds ratio and 95% confidence intervals reported.
Results
The screening criteria identified 143 pwCF that had an ETI prescription written between 8/31/2022 and 8/31/2023. Twenty-eight pwCF were excluded: Eight did not have an office visit during the study period, 12 had not transferred to adult clinic, and 8 had a lung transplant history. This resulted in 115 pwCF being included in the study population. Nearly half of pwCF were female (48.7%) and most had at least one F508del variant (91.3%). Table 1 outlines additional demographic details.
Demographic Information
Eighty-three pwCF in the study population had a PCP identified in the EMR; however, 14 of them identified PCPs who were members of the CF care team. Therefore, these patients were reclassified as not having a PCP. After this adjustment, 60% (69/115) of pwCF had a PCP and 40% (46/115) of pwCF did not.
Systolic and diastolic BP averages were comparable between groups. Of those with a recorded BP and a PCP, 76.5% (52/68) had uncontrolled BP compared to 78.3% (36/46) of pwCF without a PCP.
PwCF with a PCP had an average BMI of 26.29 kg/m2 (overweight), while those without a PCP had an average BMI of 24.20 kg/m2 (normal). Among those with weight and height measured during their CF appointments, 56% (35/62) of pwCF with a PCP were overweight or obese compared to 36% (16/44) of pwCF without a PCP. Categorization of blood pressure and weight control for pwCF are further described in Table 2.
Categorization of Blood Pressure and Weight Control for People with Cystic Fibrosis (PwCF)
Table 3 describes eligibility and completion of preventative health screenings and vaccinations in pwCF. Of those eligible, 31.3% (10/32) with a PCP were overdue for a lipid screening versus 8.3% (1/12) without a PCP. All pwCF were eligible for osteoporosis screening. Of the pwCF who had a PCP and those that did not, 31.9% (22/69) and 34.8% (16/46) were overdue for screening, respectively.
Percentage of People with Cystic Fibrosis (PwCF) Who Are Eligible and Overdue for Preventative Health Screenings and Vaccinations
Among those eligible, 56.7% (17/30) with a PCP were overdue for a colonoscopy, compared to 72.7% (8/11) without a PCP. For mammograms, 60% (6/10) of those eligible with a PCP were overdue for a mammogram. Zero pwCF without a PCP were eligible for a mammogram.
All pwCF were eligible for the primary COVID vaccination series, influenza, pneumococcal, and Tdap vaccines. In pwCF with an identified PCP, 15.9% (11/69), 28.9% (20/69), 60.9% (42/69), and 33.3% (23/69) were overdue for each vaccination, respectively. In pwCF without an identified PCP, vaccination rates were lower in each category with 28.3% (13/46), 54.3% (25/46), 84.8% (39/46), and 50% (23/46) overdue, respectively. Differences were significant for influenza (p=0.006) and pneumococcal (p=0.006) vaccinations. Of the pwCF with a PCP, 71.4% (10/14) of those eligible were overdue for a shingles vaccine, compared to 75% (3/4) of those without a PCP.
Discussion
With the advent of CFTR modulators and extending life spans for pwCF, integration of primary care services into routine CF care should be emphasized. This study illustrates that a majority of pwCF at our center have a PCP. However, 40% of pwCF did not have a PCP, which closely corresponds to the estimated one-third of Americans that do not have a PCP according to the 2023 report from the National Association of Community Health Centers.19 Our single CF center report illustrates how healthcare screenings and immunizations could be more up to date. A significant proportion of pwCF have PCPs documented within the EMR, yet these clinicians may see CF patient care as outside their purview and fail to embrace primary care management. This reinforces the need for greater education of PCPs regarding the current treatment and monitoring guidelines for pwCF.
We anticipate that improved BP management strategies will be necessary to reduce risk of heart disease and chronic kidney disease among pwCF. We found similar BP measurements and uncontrolled hypertension regardless of the managing clinician. The impact of high-salt diet and nephrotoxic medications (e.g., aminoglycosides) on BP management should be explored as treatment responses may differ from the general population. This offers a promising focus for future research.
Similarly, strategies for weight loss and diet modification can be challenging due to past recommendations for high-fat, high-calorie diets. Over half of pwCF with a PCP were overweight or obese, highlighting the need for interventions promoting healthy nutrition and exercise. Such intervention falls naturally into the primary care setting and will be essential in the post-CFTR modulator era. The pancreatic sufficient subset of pwCF may face an additional risk of pancreatitis when using weight loss medications. This question will require larger scale studies to fully characterize whether an actual threat exists.
Osteoporosis and colonoscopy screenings for pwCF occur earlier than for the general population. Collaboration between the CF care team and PCPs for scheduling screenings and interventions is essential.
Vaccination promotion in pwCF remains a significant value to public health efforts. PwCF with a PCP have higher vaccination rates, but improvements are needed. Accurate input into state vaccination registries will ensure up-to-date vaccination status across care locations.
We acknowledge limitations to our study. Documentation of PCPs in the EMR may be inaccurate. Even if patients have a PCP documented in the EMR, the frequency of follow-up remains unknown. Singular data points also pose difficulty in interpretation; for example, a singular BP measurement may have been measured incorrectly leading to miscategorization as well as potential for influence by white coat hypertension. Further, out of state vaccinations may not be reported in the EMR. Lastly, we also chose to limit our patient population to those prescribed ETI as access to HEMT has been the primary driver for increased life expectancy. While patients not receiving ETI therapy could benefit from an established relationship with a PCP, this constraint restricts generalizing our results to the entire CF population.
Given similarities in screening and treatment recommendations for pwCF and the general population, general practitioners should not shy away from providing such for pwCF. We acknowledge there are differences in some screening recommendations (e.g., colonoscopy) and noted variance in guidance for administration of pneumococcal vaccines. Better communication between the PCP and the CF care team will enhance patient care.
Strategies to close gaps between specialty and primary care will be imperative to adjust to an aging CF population. Pharmacists could provide valuable support by ensuring appropriate follow-up of primary care conditions through pharmacy management-based services. Future developments could include collaborative practice protocols for immunizations, enhanced EMR support to identify interventions, as well as improved communication and educational sessions to facilitate coordination of care.
Acknowledgments
Conceptualization, Methodology, Investigation, Validation, Formal analysis, Writing – original draft, Writing – review & editing, Project administration: Kendall Kolk. Writing – review & editing: Douglas Hornick. Writing – review & editing: Tahuanty Pena. Conceptualization, Methodology, Validation, Writing – original draft, Writing – review & editing, Supervision, Project administration: Brittany Wright.
Notes
This article was externally peer reviewed.
Funding: This research did not receive funding from funding agencies in the public, commercial, or not-for-profit sectors.
Conflict of interest: The authors have no financial interests or conflicts of interest to disclose.
- Received for publication February 21, 2025.
- Revision received March 21, 2025.
- Revision received July 19, 2025.
- Accepted for publication August 4, 2025.
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