Incidence and Prevalence of Cough in a Rural Health System: A 20-Year Study.

OBJECTIVE: Understanding the cough population is critical to addressing clinical needs and gaps in best practice. We sought to characterize and stratify cough patients with the hypothesis that there are opportunities to improve access to care in our health system and characterize the population. METHODS: Following institutional review board exempt status, a retrospective electronic record review was performed on all patients coded with ICD-9 786.2 or ICD-10 is R05 from January 1, 2001 through December 31, 2020 at our health system. Inclusion criteria were one or more visits for cough. The subgroup with more than one visit in each of 2 years was classified as multiple encounters. Patients were characterized by sex, age at first cough encounter, number of cough encounters, smoking status, and insurance status. Results were stratified by year, calculating frequencies, and percentages. RESULTS: There were 302,284 unique patients diagnosed with cough, among 1,764,387 patients seen in our health system, representing an average incidence of 3.0% (2.7%-3.7%) and prevalence of 4.9% (3.1%-5.6%). New single encounter cough patients totaled 179,963, and new multiple encounter cough patients totaled 122,321. Of the 39,828,073 total encounters, there were 469,802 for new or existing cough (1.17%-1.73% annually). The age at initial presentation demonstrated 36.5% seen <10 years old, with an even distribution over the remaining decades of life. The majority were seen for cough once, but 23.8% of group two patients had two or more visits for cough in a year. CONCLUSION: We demonstrate a lower-than-expected incidence and prevalence of cough in our health population, suggesting challenges with access to care when compared to 10% prevalence and 3% of encounters previously documented in the literature. The study also provides a platform to explore the importance of pediatric cough, as well as population health and the longitudinal journey of cough patients in underserved areas. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:1191-1196, 2023.

Impact of tenofovir on renal function in HIV-infected, antiretroviral-naive patients.

OBJECTIVE: To better characterize the long-term effects of tenofovir on renal function in a large managed care organization. METHODS: We performed a retrospective cohort analysis in Kaiser Permanente for years 2002 to 2005 comparing renal function among antiretroviral naïve patients initiating a tenofovir-containing regimen (964 patients) or tenofovir-sparing regimens (683 patients). We evaluated glomerular filtration rate (GFR, [Modification of Diet in Renal Disease equation]), serum creatinine, and the development of renal proximal tubular dysfunction. We report multivariable hazard ratios (HR, Cox modeling) and linear outcomes (repeated measures) with predictors retained if P < 0.10 (backward selection). Potential predictor variables included in multivariate models were age, sex, Black race, baseline laboratories (including CD4 count), history of diabetes mellitus, hypertension, malignancy, hepatitis, and concurrent medications. RESULTS: Overall, tenofovir-exposed patients had a larger relative decline in GFR through 104 weeks (-7.6 mL/min/1.73 m(2) relative to tenofovir-sparing, P < 0.001); the degree of the difference varied by baseline GFR, with the greatest effect seen in those patients with GFR greater than 80 mL/min/1.73 m(2). Tenofovir-exposed patients had greater development of proximal tubular dysfunction over time (at 52 wk: HR(adjusted) = 1.95 [P = 0.01] and at 104 wk: HR(adjusted) = 5.23 [P = 0.0004]) and had greater risk of medication discontinuation (HR(adjusted) = 1.21, P = 0.02), especially as renal function worsened. Viral control and CD4 count changes were similar between the two groups. CONCLUSIONS: Tenofovir is associated with greater effect on decline in renal function and a higher risk of proximal tubular dysfunction in antiretroviral naïve patients initiating antiretroviral therapy.