The Impact of Acute Peri-operative Particulate Matter Exposure on Endoscopic Sinus Surgery Outcomes: A Preliminary Multi-site Investigation.

BACKGROUND: Environmental exposures have been postulated to play an important role in the pathophysiology of chronic rhinosinusitis (CRS). Particulate matter (PM) is one of the most widely studied ambient air pollutants, but its peri-operative impact on CRS is unknown. OBJECTIVE: To determine the effect of acute, peri-operative PM exposure on outcomes after endoscopic sinus surgery (ESS). METHODS: Participants with CRS who self-selected ESS were prospectively enrolled. The 22-item SinoNasal Outcome Test (SNOT-22) and Medical Outcomes Study Questionnaire Short-Form 6-D (SF-6D) health utility values scores were recorded. Using residence zip codes, a secondary analysis of patient exposure to PM <2.5 µm and <10 µm (PM2.5 and PM10, respectively) was performed for the month of surgery utilizing data from Environmental Protection Agency air quality monitors. Spearman's correlation coefficients (ρ), 95% confidence intervals (CIs), and effect estimates (ß) were used to determine the magnitudes of association. Simple, multivariate regression analysis was also completed. RESULTS: One hundred and seven patients from four geographically unique institutions across the US were enrolled with a follow-up of 6 months. Patients with higher peri-operative PM2.5 exposure had less improvement in their SNOT-22 scores after ESS compared to those with less exposure using both univariate analysis (ρ = 0.26, 95% CI: 0.08, 0.43; P = .01) and after covariate adjustment with multivariate analysis (B = 1.06, 95% CI: 0.001, 2.14, P = .05). Similar associations were not found with SF-6D outcomes or with PM10 as an exposure of interest. No significant correlations were found between peri-operative PM levels and Lund-Kennedy endoscopy scores post-operatively. CONCLUSION: Preliminary data from this pilot study reveal that PM exposure at the time of ESS may negatively associate with post-operative improvement in sinonasal quality-of-life. Larger, population-based studies with more standardized PM exposure windows are needed to confirm the clinical significance of the present findings.

Health care disparities and chronic rhinosinusitis: Does neighborhood disadvantage impact outcomes in sinonasal disease?

OBJECTIVE: Socioeconomic status (SES) is linked to health outcomes but has not been well studied in patients with chronic rhinosinusitis (CRS). The area deprivation index (ADI) is a comprehensive measure of geographic SES that ranks neighborhood disadvantage. This investigation used ADI to understand the impact of neighborhood disadvantage on CRS treatment outcomes. METHODS: A total of 642 study participants with CRS were prospectively enrolled and self-selected endoscopic sinus surgery (ESS) or continued appropriate medical therapy as treatment. The 22-item SinoNasal Outcome Test (SNOT-22) and Medical Outcomes Study Questionnaire Short-Form 6-D (SF-6D) health utility value scores were recorded pre- and post-treatment. Using residence zip codes, national ADI scores were retrospectively assigned to patients. Spearman's correlation coefficients (Rs) and Cramer's V effect size (φc ) with 95% confidence interval (CI) were calculated. RESULTS: A history of ESS was associated with significantly worse ADI scores compared to no history of ESS (φc  = 0.18; 95% CI: 0.10, 0.25; p < 0.001). Baseline total SNOT-22 (Rs = 0.14; 95% CI: 0.06, 0.22; p < 0.001) and SF-6D values (Rs = -0.20; 95% CI: -0.27, -0.12; p < 0.001) were significantly negatively correlated with national ADI rank. No significant correlations between ADI and within-subject improvement, or achievement of >1 minimal clinically important difference, in SNOT-22 or SF-6D scores after treatment were found. CONCLUSIONS: Geographic socioeconomic deprivation was associated with worse baseline disease severity and history of prior surgical intervention. However, ADI did not correlate with improvement in disease-specific outcomes. The impact of socioeconomic deprivation on outcomes in CRS requires further investigation.

All chronic rhinosinusitis endotype clusters demonstrate improvement in patient-reported and clinical outcome measures after endoscopic sinus surgery.

BACKGROUND: It is unclear whether chronic rhinosinusitis (CRS) endotypes show a differential response to endoscopic sinus surgery (ESS). We explored patient mucous inflammatory cytokine expression and associations with patient-reported and clinically measured post-operative outcome measures. METHODS: Patients with CRS were prospectively recruited between 2016 and 2021 into a national multicenter, observational study. Mucus was collected from the olfactory cleft preoperatively and evaluated for 26 biomarkers using cluster analysis. Patient-reported outcome measures included the 22-item Sino-Nasal Outcome Test (SNOT-22) and Questionnaire of Olfactory Dysfunction (QOD). Additional clinical measures of disease severity included threshold, discrimination, and identification (TDI) scores using "Sniffin' Sticks" testing and Lund-Kennedy endoscopic score (LKES). RESULTS: A total of 115 patients were clustered into type 2 inflammatory, non-type 2 inflammatory, noninflammatory, and two indeterminate clusters based on individual protein levels. Overall, the type 2 inflammatory cluster was found to have the highest mean improvement in both SNOT-22 (-28.3 [standard deviation, ±16.2]) and TDI (6.5 [standard deviation, ±7.9]) scores 6 months after ESS. However, on average, all endotype clusters demonstrated improvement in all outcome measures after ESS without statistically significant between-group differences in SNOT-22 (p = 0.738), QOD (p = 0.306), TDI (p = 0.358), or LKES (p = 0.514) measures. CONCLUSIONS: All CRS endotype clusters responded favorably to surgery and showed improvements in patient-reported and objective outcome measures. Thus, ESS should be considered a more generalized CRS therapy, and benefits appear to not be limited to specific endotypes.

Does air pollutant exposure impact disease severity or outcomes in chronic rhinosinusitis?

BACKGROUND: Poor air quality increases the risk of developing chronic rhinosinusitis (CRS) and other airway diseases. However, there are limited data on air pollutants and CRS-specific disease severity. We assessed the impact of air pollutants on sinonasal-specific and general quality-of-life (QOL) measures in a multi-institutional cohort of patients with CRS. METHODS: Participants with CRS were prospectively enrolled in a cross-sectional study and self-selected continued appropriate medical therapy or endoscopic sinus surgery (ESS). The 22-item SinoNasal Outcome Test (SNOT-22) and Medical Outcomes Study Questionnaire Short-Form 6-D (SF-6D) health utility value scores were recorded. Patient exposure to air pollutants was determined using residence zip codes. Unadjusted group differences were compared, and correlation coefficients were evaluated to identify the magnitude of bivariate association. RESULTS: A total of 486 patients were enrolled and followed for a mean of 6.9 (standard deviation [SD] ± 2.3) months. Pollutant exposure did not significantly correlate with baseline SNOT-22 or SF-6D scores. Revision ESS was associated with higher median fine particulate matter (PM2.5; Δ = 0.12, [95% confidence interval {CI}: 0.003, 0.234]; p = 0.006) compared with primary surgery. PM2.5, PM10, and nitrogen dioxide concentrations (µg/m3) did not correlate with change in total SNOT-22 or SF-6D scores after treatment. Nevertheless, sulfur dioxide (SNOT-22: ρ = -0.121 [95% CI: -0.210, -0.030]; p = 0.007; SF-6D: ρ = 0.095 [95% CI: 0.002, 0.186]; p = 0.04) and carbon monoxide (SNOT-22: ρ = -0.141 [95% CI: -0.230, 0.050]; p = 0.002) exposure did correlate with these outcome measures. CONCLUSION: Air pollutants may contribute, at least in part, to disease severity in CRS; future investigation is needed to further elucidate the nature of this relationship.

Physician views of artificial intelligence in otolaryngology and rhinology: A mixed methods study.

Objective: The study aimed to investigate otolaryngologists' knowledge, trust, acceptance, and concerns with clinical applications of artificial intelligence (AI). Methods: This study used mixed methods with survey and semistructured interviews. Survey was e-mailed to American Rhinologic Society members, of which a volunteer sample of 86 members responded. Nineteen otolaryngologists were purposefully recruited and interviewed until thematic saturation was achieved. Results: Seventy-six respondents (10% response rate) completed the majority of the survey: 49% worked in academic settings and 43% completed residency 10 or fewer years ago. Of 19 interviewees, 58% worked in academic settings, and 47% completed residency 10 or fewer years ago. Familiarity: Only 8% of survey respondents reported having AI training in residency, although 72% had familiarity with general AI concepts; 0 interviewees had personal experience with AI in clinical settings. Expected uses: Of the surveyed otolaryngologists, 82% would use an AI-based clinical decision aid and 74% were comfortable with AI proposing treatment recommendations. However, only 44% of participants would trust AI to identify malignancy and 53% to interpret radiographic images. Interviewees trusted AI for simple tasks, such as labeling septal deviation, more than complex ones, such as identifying tumors. Factors influencing AI adoption: 89% of survey participants would use AI if it improved patient satisfaction, 78% would be willing to use AI if experts and studies validated the technologies, and 73% would only use AI if it increased efficiency. Sixty-one percent of survey respondents expected AI incorporation into clinical practice within 5 years. Interviewees emphasized that AI adoption depends on its similarity to their clinical judgment and to expert opinion. Concerns included nuanced or complex cases, poor design or accuracy, and the personal nature of physician-patient relationships. Conclusion: Few physicians have experience with AI technologies but expect rapid adoption in the clinic, highlighting the urgent need for clinical education and research. Otolaryngologists are most receptive to AI "augmenting" physician expertise and administrative capacity, with respect for physician autonomy and maintaining relationships with patients. Level of Evidence: Level VI, descriptive or qualitative study.

A Pressure-Based Multiphase Flowmeter: Proof of Concept.

Multiphase flowmeters (MPFMs) measure the flow rates of oil, gas, and brine in a pipeline. MPFMs provide remote access to real-time well production data that are essential for efficient oil field operations. Most MPFMs are complex systems requiring frequent maintenance. An MPFM that is operationally simple and accurate is highly sought after in the energy industry. This paper describes an MPFM that uses only pressure sensors to measure gas and liquid flow rates. The design is an integration of a previously developed densitometer with an innovative Venturi-type flowmeter. New computing models with strong analytical foundations were developed, aided by empirical correlations and machine-learning-based flow-regime identification. A prototype was experimentally validated in a multiphase flow loop over a wide range of field-like conditions. The accuracy of the MPFM was compared to that of other multiphase metering techniques from similar studies. The results point to a robust, practical MPFM.

Inflammation resolution and specialized pro-resolving lipid mediators in chronic rhinosinusitis.

INTRODUCTION: In chronic rhinosinusitis (CRS), a complex pathophysiology results from varied pro-inflammatory stimuli but is consistently characterized by classic cellular, molecular, and microbial alterations. Normally, endogenous specialized pro-resolving mediators (SPM) actively promote resolution of inflammation through numerous pathways, including those involved in host antimicrobial defense. However, these pathways appear to be disrupted in CRS. AREAS COVERED: This paper describes features of CRS in the context of chronic tissue inflammation, and potential mechanisms by which specialized pro-resolving mediators promote active resolution of tissue inflammation. EXPERT OPINION: Temporal phases of resolution must be tightly regulated to successfully resolve inflammation in CRS while preserving tissue functions such as barrier maintenance and special sensory function. Dysregulation of SPM enzymatic pathways has been recently shown in CRS and is associated with disease phenotypes and microbial colonization patterns. Current research in animal models and in vitro human cell culture, as well as human dietary studies, demonstrate relevant changes in cell signaling with lipid mediator bioavailability. Further clinical research may provide insight into the therapeutic value of this approach in CRS.

Otolaryngologist perceptions of AI-based sinus CT interpretation.

BACKGROUND: Overcoming non-standardization, vagueness, and subjectivity in sinus CT radiology reports is an ongoing need, particularly in keeping with data-driven healthcare initiatives. Our aim was to explore otolaryngologists' perceptions of quantitative objective disease measures as enabled by AI-based analysis, and determine preferences for sinus CT interpretation. METHODS: A multi-methods design was used. We administered a survey to American Rhinologic Society members and conducted semi-structured interviews with a purposeful sample of otolaryngologists and rhinologists from varying backgrounds, practice settings and locations during 2020-2021. Interview topics included sinus CT reports, familiarity with AI-based analysis, and potential requisites for its future implementation. Interviews were then coded for content analysis. Differences in survey responses were calculated using Chi-squared test. RESULTS: 120 of 955 surveys were returned, and 19 otolaryngologists (8 rhinologists) were interviewed. Survey data revealed more trust in conventional radiologist reports, but that AI-based reports would be more systematic and comprehensive. Interviews expanded on these results. Interviewees believed that conventional sinus CT reports had limited utility due to inconsistent content. However, they described relying on them for reporting incidental extra-sinus findings. Reporting could be improved with standardization and more detailed anatomical analysis. Interviewees expressed interest in AI-derived analysis given potential for standardization, although they desired evidence of accuracy and reproducibility to gain trust in AI-based reports. CONCLUSIONS: Sinus CT interpretation has shortcomings in its current state. Standardization and objectivity could be aided with deep learning-enabled quantitative analysis, although clinicians desire thorough validation to gain trust in the technology prior to its implementation.

Variability in P2X receptor composition in human taste nerves: implications for treatment of chronic cough.

Background: Antagonists to the P2X purinergic receptors on airway sensory nerves relieve refractory or unexplained chronic cough (RCC/UCC) but can evoke unwanted dysgeusias because the gustatory nerves innervating taste buds express this same family of receptors. However, the subunit composition of the P2X receptors in these systems may differ, with implications for pharmacological intervention of RCC/UCC. In most species, the extrapulmonary airway nerves involved in cough predominantly express P2X3 subunits that form homotrimeric P2X3 receptors. In contrast, most sensory nerves innervating taste buds in mice express both P2X2 and P2X3 subunits, so the majority of receptors in that system are likely P2X2/P2X3 heteromers. Methods: Since neural P2X subunit composition can differ across species, we used immunohistochemistry to test whether taste nerves in humans and rhesus macaque monkeys express both P2X2 and P2X3 as in mice. Results: In taste bud samples of fungiform papillae and larynx from humans and monkeys, all taste bud samples exhibited P2X3+ nerve fibres, but the majority lacked substantial P2X2+. Of the 35 human subjects, only four (one laryngeal and three fungiform) showed strong P2X2 immunoreactivity in taste nerves; none of the rhesus monkey samples showed immunoreactivity for P2X2. Conclusions: These findings suggest that for most humans, unlike mice, taste buds are innervated by nerve fibres predominantly expressing only P2X3 homomeric receptors and not P2X2/P2X3 heteromers. Thus, antagonists specific for P2X3 homomeric receptors might not be spared from affecting taste function in RCC/UCC patients.

Pneumocephalus following sneeze suppression.

Pneumocephalus is defined as air in the intracranial space. It is commonly caused by traumatic skull fractures and is diagnosed by head plain computer tomography. Treatment involves initial stabilization of vital signs and surgical intervention if symptoms do not resolve. We report a unique case of pneumocephalus following sneeze suppression.

Bacterial communities in the nasal passage of postviral olfactory dysfunction patients.

KEY POINTS: Bacterial composition is uniform in the sinuses of postviral olfactory dysfunction patients. Significant reduction of genus Corynebacterium in PVOD patients compared to controls.

Signatures for viral infection and inflammation in the proximal olfactory system in familial Alzheimer's disease.

Alzheimer's disease (AD) is characterized by deficits in olfaction and olfactory pathology preceding diagnosis of dementia. Here we analyzed differential gene and protein expression in the olfactory bulb (OB) and tract (OT) of familial AD (FAD) individuals carrying the autosomal dominant presenilin 1 E280A mutation. Compared to control, FAD OT had increased immunostaining for ß-amyloid (Aß) and CD68 in high and low myelinated regions, as well as increased immunostaining for Iba1 in the high myelinated region. In FAD samples, RNA sequencing showed: (1) viral infection in the OB; (2) inflammation in the OT that carries information via entorhinal cortex from the OB to hippocampus, a brain region essential for learning and memory; and (3) decreased oligodendrocyte deconvolved transcripts. Interestingly, spatial proteomic analysis confirmed altered myelination in the OT of FAD individuals, implying dysfunction of communication between the OB and hippocampus. These findings raise the possibility that viral infection and associated inflammation and dysregulation of myelination of the olfactory system may disrupt hippocampal function, contributing to acceleration of FAD progression.

Sex Differences in Presentation and Surgical Outcomes From a Prospective Multicenter Chronic Rhinosinusitis Study.

OBJECTIVE: Despite extensive research into chronic rhinosinusitis (CRS) epidemiology, presentation, and outcomes, there is scant knowledge on sex-specific differences. The objective of this study was to identify differences between male and female patients with CRS in baseline disease severity at presentation, choice for surgery vs continued medical treatment, and postoperative response. STUDY DESIGN: We evaluated data on demographic and health characteristics, clinical objective disease measures, and sinus-specific and general health patient-reported outcome measures. SETTING: Secondary analysis of prospective multicenter outcome study. METHODS: Comparison of cohort characteristics and baseline and postoperative measures was performed with a t test, chi-square test of independence, or Fisher exact test. Within-subject improvement was compared between sexes with a linear mixed model. RESULTS: Females reported worse quality of life on presentation and postsurgery, despite experiencing less severe disease by standard clinical measures. Overall, females and males showed similar within-subject improvement after surgery. However, certain quality of life domains and disease measures showed sex-specific improvement. Females demonstrated greater within-subject improvement in SF6D-derived health utility and the SNOT-22 ear and facial, psychological, and sleep subdomains, although this did not reach statistical significance for the overall cohort. CONCLUSION: Incorporating data on sex-specific differences may be important to personalize CRS treatment decision making. The discordance between patient-reported and clinical measures in CRS has been demonstrated in other pathologies and appears to be exaggerated by sex. Biological and psychological bases for sex-specific differences in CRS manifestations are an intriguing topic for further research.

Profiles of Odorant Specific Performance in Olfactory Testing.

BACKGROUND: Olfactory dysfunction (OD) can occur from a variety of etiologies. However, there are few reports examining whether varying etiologies have unique profiles of psychophysical testing that may provide insight into the pathophysiology of OD. METHODS: Adults with chronic rhinosinusitis with and without nasal polyps (CRSwNP/CRSsNP) and healthy control adults with no sinus complaints underwent olfactory assessment with Sniffin' Sticks. Profiles of identification and discrimination were compared between CRS and non-CRS subjects across the spectrum of OD. RESULTS: Normosmics with or without CRS identified apple, pineapple, and turpentine less frequently than expected (range 52%-68% correct). Hyposmics with CRS correctly identified orange more frequently than control hyposmics (83%-93% vs 68% for controls) with similar findings for rose. Hyposmics of all cohorts were unable to identify apple (26%). Discrimination profiles were similar across the spectrum of OD and between diagnostic groups. CONCLUSIONS: Identification and discrimination rates of specific odorants may provide unique information regarding the etiology of OD, however psychophysical testing is a complex interplay of olfactory and trigeminal function, the strength of target odorant, distractor choices, and familiarity with odorants.

Work productivity and activity impairment in patients with chronic rhinosinusitis undergoing endoscopic sinus surgery-A prospective, multi-institutional study.

BACKGROUND: Productivity loss and activity limitations due to chronic rhinosinusitis (CRS) are known to contribute to the significant economic and personal burden of disease. The purpose of this study was to assess productivity and activity impairment before and after endoscopic sinus surgery (ESS) for medically refractory CRS. METHODS: This investigation was a prospective, multi-institutional, observational cohort study. Patients diagnosed with medically refractory CRS completed the Work Productivity and Activity Impairment-Specific Health Problem (WPAI-SHP) questionnaire before surgery and approximately 6 months after the procedure. Factors associated with minimal clinical important differences (MCIDs) for productivity and activity impairment were identified. RESULTS: A total of 279 study participants were screened for inclusion, of whom 176 (63.1%) with postoperative follow-up were included in the final cohort. Preoperative productivity and activity impairment were observed in 63.2% and 69.8% of the patients, respectively. Among these patients, postoperative improvement equaling at least 1 MCID was reported in both productivity (76.1%) and activity (76.4%) impairments. Multivariate regression identified sphenoidotomy (odds ratio [OR], 4.18; 95% confidence interval [CI], 1.03-17.02) as the only factor associated with increased likelihood of productivity improvement, whereas septoplasty during ESS (OR, 8.45; 95% CI, 2.33-30.68) and migraine (OR, 0.35; 95% CI, 0.12-0.96) were associated with differential odds of activity improvement. CONCLUSION: CRS is associated with a substantial burden on productivity and activity that significantly improves after treatment with ESS. These data may facilitate improved patient counseling and shared decision-making regarding surgical management for CRS.

Evaluating Distance Bias in Chronic Rhinosinusitis Outcomes.

Importance: The distance traveled by patients for medical care is associated with patient outcomes (ie, distance bias) and is a limitation in outcomes research. However, to date, distance bias has not been examined in rhinologic studies. Objective: To evaluate the association of distance traveled by a cohort of patients with chronic rhinosinusitis with baseline disease severity and treatment outcomes. Design, Setting, and Participants: A total of 505 patients with chronic rhinosinusitis were prospectively enrolled in a multi-institutional, cross-sectional study in academic tertiary care centers between April 2011 and January 2020. Participants self-selected continued appropriate medical therapy or endoscopic sinus surgery. The 22-item Sinonasal Outcome Test (SNOT-22) and Medical Outcomes Study Short Form 6-D (SF-6D) health utility value scores were recorded at enrollment and follow-up. Data on the distances traveled by patients to the medical centers, based on residence zip codes, and medical comorbid conditions were collected. Exposures: Distance traveled by patient to obtain rhinologic care. Main Outcomes and Measures: SNOT-22 and SF-6D scores. Scores for SNOT-22 range from 0 to 110; and for SF-6D, from 0.0 to 1.0. Higher SNOT-22 total scores indicate worse overall symptom severity. Higher SF-6D scores indicate better overall health utility; 1.0 represents perfect health and 0.0 represents death. Results: The median age for the 505 participants was 56.0 years (IQR, 41.0-64.0 years), 261 were men (51.7%), 457 were White (90.5%), and 13 were Hispanic or Latino (2.6%). These categories were collected according to criteria described and required by the National Institutes of Health and therefore do not equal the entire cohort. Patients traveled a median distance of 31.6 miles (50.6 km) (IQR, 12.2-114.5 miles [19.5-183.2 km]). Baseline (r = 0.00; 95% CI, 0.00-0.18) and posttreatment (r = 0.01; 95% CI, -0.07 to 0.10) SNOT-22 scores, as well as baseline (r = -0.12; 95% CI, -0.21 to -0.04) and posttreatment (r = 0.07; 95% CI, -0.02 to 0.16) SF-6D scores, were not associated with distance. There was no clinically meaningful correlation between distance traveled and mean comorbidity burden. Nevertheless, patients with a history of endoscopic sinus surgery were more likely to travel longer distances to obtain care (Cliff delta = 0.28; 95% CI, 0.19-0.38). Conclusions and Relevance: Although this cross-sectional study found that some patients appear more willing to travel longer distances for chronic rhinosinusitis care, results suggest that distance traveled to academic tertiary care centers was not associated with disease severity, outcomes, or comorbidity burden. These findings argue for greater generalizability of study results across various cohorts independent of distance traveled to obtain rhinologic care. Trial Registration: ClinicalTrials.gov Identifier: NCT02720653.

Impact of Airline Secondhand Tobacco Smoke Exposure on Respiratory Health and Lung Function Decades After Exposure Cessation.

BACKGROUND: Twenty-five percent to 45% of COPD is caused by exposures other than active smoking. Secondhand tobacco smoke (SHS) has been suggested as an independent cause of COPD, based on its association with increased respiratory symptoms and a small decrease in lung function, but its impact on respiratory health and lung function after exposure cessation has not been explored. RESEARCH QUESTION: What are the consequences of airline SHS exposure on respiratory health and lung function decades after cessation? STUDY DESIGN AND METHODS: We performed a cohort study involving flight attendants because of their exposure to SHS that stopped > 20 years ago. We included subjects ≥ 50 years of age with > 1 year vs ≤ 1 year of airline SHS exposure (ie, exposed vs unexposed). Respiratory quality of life, as determined by the St. George's Respiratory Questionnaire (SGRQ), was the primary outcome for respiratory health. Key secondary outcomes included general quality of life (the Rand Corporation modification of the 36-item Short Form Health Survey Questionnaire; RAND-36), respiratory symptoms (COPD Assessment Test; CAT), and spirometry. RESULTS: The study enrolled 183 SHS-exposed and 59 unexposed subjects. Exposed subjects were 66.7 years of age, and 90.7% were female. They were hired at 23.8 years of age, were exposed to airline SHS for 16.1 years, and stopped exposure 27.5 years before enrollment. Prior SHS exposure was associated with worsened SGRQ (6.7 units; 95% CI, 2.7-10.7; P = .001), RAND-36 physical and social function, and CAT vs unexposed subjects. SHS exposure did not affect prebronchodilator spirometry or obstruction, but was associated with lower postbronchodilator FEV1 and FEV1/FVC, total lung capacity, and diffusing capacity of the lungs for carbon monoxide in a subset of subjects. Former smoking and SHS exposure synergistically worsened SGRQ (ß = 8.4; 95% CI, 0.4-16.4; P = .04). SHS exposure in people who never smoked replicated primary results and was associated with worsened SGRQ vs unexposed people (4.7 units; 95% CI, 0.7-7.0; P = .006). INTERPRETATION: Almost three decades after exposure ended, airline SHS exposure is strongly and dose-dependently associated with worsened respiratory health, but less robustly associated with airflow abnormalities used to diagnose COPD.