Clinical Focus

  • Internal Medicine

Academic Appointments

Administrative Appointments

  • Medical Director, Stanford Internal Medicine Clinic (2022 - Present)
  • Director, Continuity of Care Clerkship (2020 - Present)
  • Co-Director, Stanford Internal Medicine East Clinic (2019 - 2022)

Professional Education

  • Board Certification: American Board of Internal Medicine, Internal Medicine (2015)
  • Residency: Boston University Medical Center Internal Medicine Residency (2015) MA
  • Medical Education: Northwestern University Office of the Registrar (2012) IL

2023-24 Courses

All Publications

  • A Practical Approach to Low-Dose Aspirin for Primary Prevention. JAMA Chiang, K. F., Shah, S. J., Stafford, R. S. 2019

    View details for DOI 10.1001/jama.2019.8388

    View details for PubMedID 31251325

  • Long-Term Outcomes of Sacubitril/Valsartan in Heart Failure with Reduced Ejection Fraction and Coexisting End-Stage Renal Disease. Clinical pharmacology and therapeutics Lin, W. Y., Shao, Y. J., Chiang, A. F., Huang, C. C., Chiang, K. F., Chan, C. S., Huang, C. Y., Hsiao, B. Y. 2024


    Sacubitril/valsartan (Entresto) has proven therapeutic effects in heart failure (HF) patients, but its impact on those with advanced chronic kidney disease (CKD) remains unclear, particularly in HF patients with coexisting end-stage renal disease (ESRD). This study aims to assess the long-term survival of patients with heart failure with reduced ejection fraction (HFrEF) and coexisting ESRD treated with sacubitril/valsartan. A retrospective cohort study included 2,860 HFrEF and ESRD patients between January 2008 and December 2020. After propensity score matching, data from a sacubitril/valsartan group (n = 61) and a candesartan or valsartan group (n = 117) were analyzed. Patients on sacubitril/valsartan for at least 9 months had significantly lower 5-year all-cause mortality (39.3%) compared with the non-sacubitril/valsartan group (54.7%) (HR 0.46; 95% CI, 0.25-0.82; P = 0.0094). Left ventricular ejection fraction (LVEF) improvement after 3 years in the sacubitril/valsartan group (14.51 ±18.98) was significantly greater than the non-sacubitril/valsartan group (6.91 ±18.44) (P = 0.0408). Average hospitalizations in sacubitril/valsartan and non-sacubitril/valsartan groups were 1.39 and 0.97, respectively (incidence rate ratio, 1.59; 95% CI, 0.90-2.82; P = 0.1106). Sacubitril/valsartan treatment demonstrated significantly lower 5-year mortality rates and greater LVEF improvement in HFrEF patients with coexisting ESRD compared with candesartan or valsartan. These findings suggest that sacubitril/valsartan is a beneficial treatment option for this patient population.

    View details for DOI 10.1002/cpt.3315

    View details for PubMedID 38880970

  • Training Internal Medicine Residents in Difficult Diagnosis: A Novel Diagnostic Second Opinion Clinic Experience. Journal of medical education and curricular development Testa, S., Joshi, M., Lotfi, J., Lin, B., Artandi, M., Chiang, K. F., Chang, K., Singh, B., Geng, L. N. 2022; 9: 23821205221091036


    Background: In primary care clinics, time constraints and lack of exposure to highly complex cases may limit the breadth and depth of learning for internal medicine residents. To address these issues, we piloted a novel experience for residents to evaluate patients with puzzling symptoms referred by another clinician.Objective: To increase internal medicine residents' exposure to patients with perplexing presentations and foster a team-based approach to solving diagnostically challenging cases.Methods: During the academic year 2020-2021, residents participating in their 2-week primary care "block" rotation were given protected time to evaluate 1-2 patients from the Stanford Consultative Medicine clinic, an internist-led diagnostic second opinion service, and present their patients at the case conference. We assessed the educational value of the program with resident surveys including 5-point Lickert scale and open-ended questions.Results: 21 residents participated in the pilot with a survey response rate of 66.6% (14/21). Both the educational value and overall quality of the experience were rated as 4.8 out of 5 (SD 0.4, range 4-5; 1:"very poor"; 5:"excellent"). Residents learned about new diagnostic tools as well as how to approach complex presentations and diagnostic dilemmas. Residents valued the increased time devoted to patient care, the team-based approach to tackling difficult cases, and the intellectual challenge of these cases. Barriers to implementation include patient case volume, time, and faculty engagement.Conclusions: Evaluation of diagnostically challenging cases in a structured format is a highly valuable experience that offers a framework to enhance outpatient training in internal medicine.

    View details for DOI 10.1177/23821205221091036

    View details for PubMedID 35372696

  • Current Prescribing Practices and Guideline Concordance for the Treatment of Uncomplicated Urinary Tract Infections in Women. American journal of obstetrics and gynecology Langner, J. L., Chiang, K. F., Stafford, R. S. 2021


    BACKGROUND: Uncomplicated urinary tract infections are one of the most common bacterial infections in the United States. Clinical practice guidelines from the Infectious Diseases Society of America recommend nitrofurantoin, trimethoprim-sulfamethoxazole and fosfomycin as first-line antibiotic treatments, and discourage the use of fluoroquinolone antibiotics. The United States Food and Drug Administration released several black box warnings about fluoroquinolones over the past decade due to antibiotic resistance and a high burden of adverse events. Historically, uncomplicated urinary tract infections have high rates of guideline-discordant treatment with past studies noting substantial use of fluoroquinolones, directly contradicting clinical practice guidelines.OBJECTIVE: To assess the current concordance of physician prescribing practices with Infectious Diseases Society of America guidelines for the treatment of uncomplicated urinary tract infections in women and identify patient and physician predictors of guideline concordance.STUDY DESIGN: A retrospective observational secondary analysis was conducted using a series of cross-sectional data extracted from the IQVIA (Plymouth Meeting, PA) National Disease and Therapeutic Index from 2015-2019. An estimated 44.9 million women with uncomplicated urinary tract infections ages 18-75 years were treated as outpatients. This population was selected to lack relevant comorbidities or urological abnormalities so that it matched the Infectious Diseases Society of America guidelines. The proportion of prescriptions for each antibiotic drug class were reported with 95% confidence intervals and compared to the Infectious Diseases Society of America guidelines. Patient and physician characteristics were included in a multivariate logistic regression model to identify independent predictors of antibiotic selection and thereby guideline concordance.RESULTS: Of the visits that resulted in antibiotic treatment, the overall concordance rate was 58.4% (26.2 M visits/44.9 M visits) and increased from 48.2% (3.9 M visits/8.1 M visits) in 2015 to 64.6% (6.3 M visits/9.8 M visits) in 2019. The most commonly prescribed antibiotics were fluoroquinolones (36.4%, 16.3 M visits/44.9 M visits), nitrofurantoin (31.8%, 14.3 M visits/44.9 M visits) and trimethoprim-sulfamethoxazole (26.3%, 11.8 M visits/44.9 M visits). From 2015 to 2019 fluoroquinolone use decreased while nitrofurantoin and beta-lactam use increased. Based on the logistic regression, patients ages 18-29 years (OR 1.60, 95% CI 1.36-1.88, p<0.001) and 30-44 years (OR 1.21, 95% CI 1.03-1.42, p=0.020) had a statistically significantly higher likelihood of receiving guideline-concordant treatment compared to patients ages 45-75 years (reference group). Obstetricians/gynecologists (OR 3.56, 95% CI 2.91-4.37, p<0.001) and urologists (OR 3.51, 95% CI 2.45-5.13, p<0.001) had a statistically significantly higher likelihood of concordant treatment compared to all other specialties combined (reference group).CONCLUSION: Guideline discordance continues in the treatment of uncomplicated urinary tract infections with the overuse of fluoroquinolones and the underuse of first-line antibiotics. Although improving, continued misuse of antibiotics may contribute to the growing rates of antibiotic resistance. Actions such as educating physicians about antibiotic resistance and clinical practice guidelines, and providing feedback on prescription habits are needed to increase guideline concordance and therefore reduce the use of fluoroquinolones, especially for physicians in family and internal medicine.

    View details for DOI 10.1016/j.ajog.2021.04.218

    View details for PubMedID 33848538