Background:Bronchoscopic lung volume reduction with endobronchial valves (BLVR-EBV) is a proven symptomatic treatment for advanced emphysema. Conflicting findings on the lobar effects post-treatment are noted in the literature. Our inhouse software for quantitative ventilation/perfusion scan (qVQ) with single photon emission computed tomography (SPECT) and low-dose computed tomography (CT) quantifies lobar ventilation radioactivity (Vent%), perfusion radioactivity (Perf%) and volume (Vol%) as percentages of total lung; and the product of lobar ventilation and perfusion per unit volume, as an index of differential contribution to total lung function [VQ capacity differential index (VQCDI)]. We coined other indices to evaluate: parenchymal function [VQ differential index (VQDI) = (Vent%/Vol%) × (Perf%/Vol%)]; and lobar gas trapping (VQCDI/Vol%). We evaluated lobar changes post BLVR-EBV using these qVQ parameters and emphysema ratio % (ER%) from quantitative CT (qCT). Methods:Pre and post BLVR-EBV qVQ and qCT were performed in a study (EMPHYSISE) with a primary aim of evaluating cardiopulmonary remodelling. A multidisciplinary panel determined the treatment indication and target lobe (TL) selection. Post-treatment cardiopulmonary exercise test (CPET) and pulmonary function test (PFT) were included. Pre- vs. post-BLVR-EBV qVQ and qCT parameters were analysed with the Wilcoxon signed-rank test for significant differences. The mean difference of Vent%, Perf%, Vol% of each lobe evaluated the redistribution to non-treated lobes; Vent%/Vol% and Perf%/Vol% evaluated the dilutional effect of increased volume; VQCDI, VQCDI/Vol% and VQDI evaluated lobar functional changes. Results:Ten of 13 participants had pre- and post- (<12 months) BLVR-EBV qVQ. TL: 4 left upper lobe (LUL), 5 left lower lobe (LLL), 1 combined right upper lobe (RUL)/right middle lobe (RML). Post-BLVR-EBV CPET in 9 and PFT in 9. All ten achieved at least 1 treatment response threshold. All paired comparisons reached statistical significance except for 3 pairs. For TL: marked reduction of all indices, even with subtotal collapse as low as 27.7% Vol% reduction. The ipsilateral untreated lobe (IUL): received highest volume, ventilation and perfusion redistributions (mean increases of >61%), mild dilution in ventilation but not perfusion; highest mean VQCDI increase (11%); minor mean VQCDI/Vol% worsening (-0.1); mild mean VQDI worsening (-0.2); highest mean ER% improvement (-3.5%). In the contralateral lung, the lower lobe (C-LL) had: highest redistributions (>19%); minor ventilation and perfusion dilution; the highest VQCDI improvement (+4.2%); minor VQCDI/Vol% worsening (-0.05); minor VQDI worsening (-0.1); mild ER% improvement (-0.6%). Conclusions:Our study indicates that following BLVR-EBV, the TL suffers marked functional decline even with subtotal collapse. IUL benefits the most functionally. C-LL benefits the most in the contralateral lung. By implication, pre BLVR-EBV assessment using qVQ and qCT should ideally target the most diseased lobe that is paired with the healthiest IUL to maximise functional outcome. Further larger studies with longer follow-up would be beneficial.

Background Peripheral pulmonary nodules (PPNs) are increasingly detected through lung cancer screening. Conventional navigation techniques like bronchial branch tracing with radial endobronchial ultrasound (r-EBUS), lack ‘tool-in-lesion’ confirmation, limiting diagnostic yield. Cone-beam computed tomography (CBCT) addresses this gap. This study aimed to evaluate the feasibility of integrating CBCT into an established bronchial branch tracing and r-EBUS workflow as a targeted tool-in-lesion confirmation strategy Method This prospective, single-centre observational study compared standard bronchial branch tracing with r-EBUS against the same workflow with CBCT used for tool-in-lesion confirmation. Consecutive patients undergoing bronchoscopy for PPNs under general anaesthesia were enrolled with allocation determined by CBCT availability. Feasibility was determined by the primary endpoint of navigational yield. Secondary outcomes included diagnostic yield, procedural time, radiation exposure and safety. Results Forty patients were analysed (n=20 CBCT, n=20 standard of care). Demographic and nodule characteristics were similar between groups. In the CBCT arm, navigational yield with bronchial branch tracing alone was 75% increasing to 90% with CBCT guided re-navigation. Diagnostic yield was 80% in CBCT compared to 65% in standard of care(p=0.29). Procedure suite time was modestly increased (54.95 vs 49.65minutes, p=0.03) while anaesthesia and bronchoscopy times were similar. No complications occurred in the CBCT arm. Radiation exposure was higher with CBCT (mean total dose 3.9mSv vs 0.35mSv). Conclusion: Selective use of CBCT as a tool-in-lesion confirmation modality is feasible and can enhance navigational yield and diagnostic yield when added to a conventional bronchial branch tracing and r-EBUS workflow with minimal impact on procedural time. Despite an increase in radiation exposure, these findings support CBCT as a practical means of strengthening existing bronchoscopic workflows.

Background Globally, adult Indigenous people, including Aboriginal Australians, have a high burden of chronic respiratory disorders, and bronchiectasis is no exception. However, literature detailing bronchiectasis disease characteristics among adult Indigenous people is sparse. This study assessed the clinical profile of bronchiectasis among adult Aboriginal Australians and compared against previously published international bronchiectasis registry reports.Methods Aboriginal Australians aged >18 years with chest CT confirmed bronchiectasis between 2011 and 2020 in the Top End Northern Territory of Australia were included. Demographics, chest CT findings, pulmonary function results, sputum microbiology, coexistent medical comorbidities, and pharmacotherapy use were assessed and compared against five published international bronchiectasis registry reports (Australian (ABR), European (European Multicentre Bronchiectasis Audit and Research Collaboration (EMBARC)-Europe), Indian (EMBARC-India), Korean (KMBARC) and the USA (USBRR)).Results A total of 459 patients were assessed. In comparison with international and non-Aboriginal Australian national cohorts, Aboriginal Australians were younger (median 56 years (IQR (48, 65)); however, sex distribution (55% female) and body mass index (23 kg/m2 (IQR 19.4–27)) were comparable . Smoking rates were higher at 85% compared with other registry cohorts (22–46%) as was the prevalence of comorbidities (97%): cardiovascular diseases (73%), diabetes mellitus (50%) and chronic obstructive pulmonary disease (83%) compared with other registry cohorts (4–32%; 6–14%; and 14–37%, respectively). Spirometry demonstrated forced expiratory volume in 1 s of 38% predicted in comparison with 61–77% in other cohorts. Sputum microbiology showed Haemophilus influenzae (57%) isolated at 3.4 to 6 times the rate of other registry cohorts and Pseudomonas aeruginosa in 31%. Chest CT demonstrated multilobar and lower lobes involvement in 73% and inhaled pharmacotherapy use was recorded in up to 62% and long-term antibiotics in 5%.Conclusion The overall bronchiectasis disease burden is higher in Aboriginal Australian adults in comparison with global ethnically diverse non-Indigenous populations. Further efforts are required to address this disparity secondary to bronchiectasis among Indigenous people.

BACKGROUND:Endobronchial valve (EBV) insertion for lung volume reduction is a management option for patients with severe emphysema. One-way valves cause lobar deflation and improve lung function, exercise capacity and quality of life. AIMS:To retrospectively analyse and compare the outcomes of the first 57 patients treated with EBVs between 2015 and 2021 at the Royal Adelaide Hospital to international standards. METHODS:Clinical outcomes of forced expiratory volume in 1 s (FEV1), residual volume (RV), treated lobe volume reduction (TLVR) and 6-min walk distance (6MWD) at 3, 6 and 12 months after valve insertion were reviewed against established minimally clinically important differences (MCIDs). Complications and subjective breathlessness measured by Borg scores were also reviewed. RESULTS:Fifty-seven patients were included. At 12 months, 77.2% achieved TLVR. FEV1 improved by 170 mL (95% confidence interval (CI): 100-250, P < 0.001), 80 mL (95% CI: 10-150, P = 0.019) and 40 mL (95% CI: -60 to 130, P 0.66) at 3, 6 and 12 months respectively. RV improved by -610 mL (95% CI: -330 to -900, P < 0.0001) at 3 months, -640 mL (95% CI: -360 to -920, P < 0.0001) at 6 months and -360 mL (95% CI: -60 to -680, P = 0.017) at 12 months. 6MWD improved by 57.34 m (95% CI: 36.23-78.45, P < 0.0001) and 44.93 m (95% CI: 7.19-82.67, P = 0.02) at 3 and 6 months. Borg score improved by -0.53 (95% CI: 0.11 to -1.2, P = 0.11) and -0.49 (95% CI: 0.17 to -1.15, P = 0.16) at 3 and 6 months. Complication rates aligned with international standards with mucous/infection (26.3%) and pneumothorax (17.5%) as the most common. Subgroup analysis signalled improved outcomes in patients with heterogeneous emphysema. CONCLUSION:Our study represents the first publicly funded Australian analysis of EBVs. The results align with international prospective trials demonstrating improved lung function and exercise capacity. Australians with severe emphysema and gas trapping should be referred to a multidisciplinary centre for consideration of EBVs.

Background:Identification of peripheral pulmonary nodules (PPNs) is becoming increasingly common with modern imaging and lung cancer screening programs. Navigational bronchoscopy has been developed to augment the diagnostic yield of sampling these nodules. Cone beam CT (CBCT) scan is one navigational tool which can be used alongside the historical criterion standard of fluoroscopy and radial endobronchial ultrasound (r-EBUS). Research Question:What is the diagnostic yield and safety profile of combining CBCT scan with r-EBUS for the diagnosis of PPNs? Study Design and Methods:Embase, PubMed, and Cochrane Central Register of Controlled Trials were searched in March 2023. Eligible studies used CBCT scan with r-EBUS as the primary navigation technique. The primary outcome, diagnostic yield, was analyzed using random effects meta-analysis. Additional subgroup analysis was based on the use of additional navigational technologies. Risk of bias was assessed using the Critical Appraisal Skills Programme tool for diagnostic studies. The Grading of Recommendations Assessment, Development, and Evaluation tool was used to assess the quality of outcomes. Results:Fourteen studies (865 patients and 882 lesions) were included. The risk of bias was significant as assessed using the Critical Appraisal Skills Programme tool, which identified multiple confounders. The pooled diagnostic yield of combined CBCT scan and r-EBUS-guided biopsy for the diagnosis of PPNs was 80% (95% CI, 76%-84%). Subgroup analysis of diagnostic yield for CBCT scan and r-EBUS alone was 80% (95% CI, 76%-83%). The diagnostic yield of CBCT scan and r-EBUS combined with additional navigational technology (electromagnetic navigational bronchoscopy, virtual bronchoscopic navigation, and robotic-assisted bronchoscopy) was 80% (95% CI, 73%-87%). The quality of outcomes was assessed as low to very low using the Grading of Recommendations Assessment, Development, and Evaluation tool. There was a 2.01% pneumothorax rate and 1.08% bleeding rate. Although heterogeneously reported, the total radiation dose was between 19.59 and 85.9 Gy.cm2, resulting in an approximate effective dose range of 3.1 to 13.8 mSv. Interpretation:CBCT scan and r-EBUS for the diagnosis of PPNs has a high diagnostic yield and acceptable safety profile. Studies showed moderate heterogeneity with significant bias; hence, generalizability of the study is limited and further prospective trials are required. Clinical Trial Registration:PROSPERO; No.: CRD42023410221; URL: https://www.crd.york.ac.uk/prospero/.

Assessing autophagy promises to provide valuable information regarding the pathogenesis of chronic obstructive pulmonary disease (COPD). However, measuring the dynamic aspect of autophagy is challenging, and sample manipulation can cause signal fluctuations that deviate from the situation in vivo . Our aim was to assess an organotypic method to quantify autophagy in the context of COPD, where autophagy has demonstrated disease-related modulation. Blood from control and COPD participants was treated with/out chloroquine. Protein from peripheral blood mononuclear cells (PBMC) was then isolated and compared for LC3B-II abundance. Our observations show that while basal level LC3B-II abundance was similar between each group (P = 0.60), autophagic flux was significantly lower in the COPD cohort, suggesting disruption in autophagy (P = 0.004). We aim to extend this inquiry and compare pulmonary vs blood samples, to identify the utility of measuring autophagy in blood as a diagnostic outcome predictive of early COPD.### Competing Interest StatementThe authors have declared no competing interest.

We hypothesise that anti-inflammatory macrolides can alleviate both the NLRP3 inflammasome activation and accelerated senescence in alveolar macrophages in COPD and/or response to cigarette smoke. Lung tissues from COPD patients and mice chronically exposed to cigarette smoke, cultures of human primary alveolar macrophages and macrophages derived from blood (MDM) or THP-1 monocytes were analysed for markers of macrophage NLRP3 inflammasome activation and accelerated senescence using multifluorescence quantitative confocal microscopy, Western blot, flow cytometry and histochemistry. Cultured macrophages were stimulated with 10% cigarette smoke extract (CSE), with or without presence of non-antibiotic macrolides 2'-desoxy-9-(S)-erythromycylamine and azithromycin-based 2'-desoxy molecule. Cigarette smoke and CSE induced in macrophages significant (p

Background: Improvements in pulmonary diagnostic imaging and the development of lung cancer screening are increasing the prevalence of Solitary pulmonary nodules (SPNs). Fluoroscopically guided radial endobronchial ultrasound (EBUS) with transbronchial forceps biopsy (TB-FB) has been the conventional diagnostic method. Transbronchial cryobiopsy (TB-CB) is an alternative biopsy method. We sought to compare transbronchial cryobiopsy to transbronchial forceps biopsy for the diagnosis of SPNs. Methods: A prospective, single-centre, randomised controlled trial was conducted at the Royal Adelaide Hospital (RAH). Patients with SPNs were randomised to either 5 transbronchial forceps biopsies or one transbronchial cryobiopsy. Complete blinding of investigators and participants was not possible, as transbronchial cryobiopsy required general anaesthesia. The primary outcome was diagnostic yield with secondary outcomes of specimen size, diagnostic yield for subsets challenging to access with forceps and safety. Results: The overall diagnostic yield for the 28 enrolled subjects was 76.8%(22/28). The diagnostic yield was 91.7% (11/12 patients) for transbronchial cryobiopsy and 68.8% (11/16 patients) for forceps biopsy (p=0.14). Median biopsy sizes were consistently larger for the cryobiopsy arm at 7.0mm compared to 2.5mm(p<0.0001). An eccentric EBUS image signalling the probe was adjacent to the nodule occurred in 4/28 cases, and TB-CB confirmed a diagnosis in 3/3 randomised to this arm. There were no major complications with either technique. Conclusion: Transbronchial cryobiopsy under the guidance of fluoroscopy and radial EBUS facilitates larger biopsy specimens without a significant increase in major complications. Further research is required to confirm the effect on diagnostic yield; however, our study supports a role for TB-CB in the diagnosis of SPNs and small, nodule-adjacent biopsies. Clinical Trial Registration Number: Reference number of R20160213(HREC/16/RAH/37).

BackgroundAboriginal Australians are reported to have higher presence of chronic respiratory diseases. However, comprehensive evidence surrounding this is sparse. Hence, a systematic review was undertaken to appraise the current state of knowledge on respiratory health in the adult Aboriginal Australians, in particular among the three most common respiratory disorders: asthma, bronchiectasis and chronic obstructive pulmonary disease (COPD). MethodsA systematic review of primary literature published between January 2012 and October 2022, using the databases PubMed and Scopus, was conducted. Studies were included if they reported adult Aboriginal Australian prevalence's or outcomes related to asthma, bronchiectasis or COPD, and excluded if adult data were not reported separately, if Aboriginal Australian data were not reported separately or if respiratory disorders were combined into a single group. Risk of bias was assessed by both Joanne Briggs Institute checklists and Hoys' bias assessment. Summary data pertaining to prevalence, lung function, symptoms, sputum cultures and mortality for each of asthma, bronchiectasis and COPD were extracted from the included studies. ResultsThirty-seven studies were included, involving approximately 33 364 participants (71% female). Eighteen studies reported on asthma, 21 on bronchiectasis and 30 on COPD. The majority of studies (94%) involved patients from hospitals or respiratory clinics and were retrospective in nature. Across studies, the estimated prevalence of asthma was 15.4%, bronchiectasis was 9.4% and COPD was 13.7%, although there was significant geographical variation. Only a minority of studies reported on clinical manifestations (n=7) or symptoms (n=4), and studies reporting on lung function parameters (n=17) showed significant impairment, in particular among those with concurrent bronchiectasis and COPD. Airway exacerbation frequency and hospital admission rates including mortality are high. DiscussionAlthough risk of bias globally was assessed as low, and study quality as high, there was limited diversity of studies with most reporting on referred populations, and the majority originating from two centres in the Northern Territory. The states with the greatest Aboriginal Australian population (Victoria and New South Wales) reported the lowest number of studies and patients. This limits the generalisability of results to the wider Aboriginal Australian population due to significant environmental, cultural and socioeconomic variation across the population. Regardless, Aboriginal Australians appear to display a high prevalence, alongside quite advanced and complex chronic respiratory diseases. There is however significant heterogeneity of prevalence, risk factors and outcomes geographically and by patient population. Further collaborative efforts are required to address specific diagnostic and management pathways in order to close the health gap secondary to respiratory disorders in this population.

Background:Endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) is the standard for evaluating mediastinal and hilar lesions. EBUS-TBNA is limited by small volume of material obtained for immunohistochemistry (IHC) and ancillary studies important for oncological therapies. The Franseen AcquireTM needle is designed for EBUS-transbronchial needle core biopsy (TBNB) allowing larger core sizes with evidence in gastroenterology literature but little in pulmonology. This study reports the first Asia-Pacific experience of EBUS-TBNB and adequacy of samples for diagnosis and ancillary studies. Methods:A retrospective cohort study of EBUS-TBNB at the Royal Adelaide Hospital was conducted between December 2019 and May 2021. Diagnostic rate, adequacy for ancillary studies and complications were evaluated. Samples were flushed into formalin for histological processing with no rapid on-site cytological evaluation (ROSE). For suspected lymphoma, samples were flushed into HANKS for flow cytometry. Cases performed with the Olympus VizishotTM during the same 18-month were similarly analysed. Results:One hundred and eighty-nine patients were sampled with the AcquireTM needle. Diagnostic rate was 174/189 (92.1%). Where reported [146/189 (77.2%)], average core aggregate sample size was 13.4 mm × 10.7 mm × 1.7 mm. For non-small cell lung cancer (NSCLC) cases, 45/49 (91.8%) had adequate tissue for programmed cell death-ligand 1 (PD-L1). 32/35 (91.4%) adenocarcinoma cases had sufficient tissue for ancillary studies. There was one false negative malignant lymph node at the first AcquireTM procedure. There were no major complications. One hundred and one patients were sampled with the VizishotTM needle. Diagnostic rate was 86/101 (85.1%) with only 25/101 (24.8%) having reported tissue cores (P<0.0001 of VizishotTM) with the remaining samples processed via cell block. Conclusions:AcquireTM EBUS-TBNB diagnostic rate is comparable to historical data with >90% of cases having sufficient core material for ancillary studies. There appears to be a role for the AcquireTM alongside the standard of care for the work up of lymphadenopathy and particularly for lung cancer.

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INTRODUCTION:Pro-inflammatory CD8+ T cells are increased in the lungs and also in the peripheral circulation of both smokers and chronic obstructive pulmonary disease (COPD) patients. The reason for this is unclear but has been described as a spillover from cells in the lungs that may cause the systemic inflammation noted in COPD. We have recently shown an increase in steroid-resistant CD28nullCD8+ senescent lymphocytes in the lungs and peripheral blood in COPD. Leukotreine B4 (LB4) receptor 1 (BLTR1) is involved in recruitment of CD8+ T cells to sites of inflammation, and we hypothesized that it may be involved in the migration of these senescent lymphocytes from the lungs in COPD.METHODS:Via flow cytometry and Western blot BLTR1, IFNγ, and TNFα expression were measured in peripheral blood, BAL, and large proximal and small distal airway CD28±, CD8± T, and NKT-like cells from COPD patients and healthy control subjects (±prednisolone) following in vitro stimulation. Chemotaxis of leucocyte subsets was determined (±LB4 ± prednisolone).RESULTS:There was an increase in BLTR1-CD28nullCD8+ lymphocytes in the lungs and blood in patients with COPD compared with controls. BLTR1-CD28nullCD8+ T and NKT-like cells produce more IFN/TNF than BLTR+ cells and fail to migrate to LTB4. Treatment with 1 µM prednisolone in vitro resulted in upregulation of BLTR1 expression in pro-inflammatory CD28nullCD8+ cells and migration to LB4.CONCLUSIONS:Loss of BLTR1 is associated with an increased inflammatory potential of CD28nullCD8+ T cells and may allow these pro-inflammatory steroid-resistant cells to migrate to peripheral blood. Treatment strategies that upregulate BLTR1 may reduce systemic inflammation and associated co-morbidity in patients with COPD.

Aims/hypothesis: Autophagy plays a critical role in the survival and microbial clearance functions of airway epithelial cells (AEC). Contrary to the known roles of azithromycin (AZM) in promoting microbial clearance, our preliminary evidence suggests that AZM inhibits autophagy in mammalian cells - an effect that could potentially promote bacterial residency in chronic respiratory diseases. Here we investigate the structure-activity relationship of AZM vs an AZM derivative (AZM-[O]), to mitigate the off-target arrest of autophagy. Method: Participant-derived COPD vs control airway biopsies were assessed for intrinsic defects in autophagy gene activity via qRT-PCR array. For in vitro studies, the 16HBE14o- AEC line and Western blot were used to assess macrolide vs autophagy structure-activity relationships, and autophagic flux by quantifying the protein abundance of LC3B-II vs Sequestosome-1. Subsequent assessments of antimicrobial activity were conducted using an E coli model and the minimum inhibitory concentration method. Immunomodulatory outcomes were assessed by quantifying the secretion of IL-6 in an LPS-stimulated THP-1 macrophage model. Results: Signatures of transcript-abundance showed an overall reduction in autophagy gene activity in COPD vs control biopsies. AZM significantly inhibited autophagic flux, evidenced by the accumulation of LC3B-II and Sequestosome-1, compared to its precursors and other macrolides including roxithromycin and clarithromycin. Notably, oxidation of AZM to produce AZM-[O] significantly alleviated this inhibitory effect on autophagy without completely preserving its antimicrobial and immunomodulatory functions. Conclusion: The potent off-target block of autophagic flux demonstrated by AZM can be negated using a medicinal chemistry approach. We are currently investigating the AZM-protein interactome and further AZM derivatives that preserve the immunomodulatory function of the parent molecule, to provide a new therapeutic option for chronic respiratory disease and to safeguard the efficacy of AZM.### Competing Interest StatementThe authors have declared no competing interest.

We previously showed increased steroid resistant CD28null CD8+ senescent lymphocyte subsets in peripheral blood from COPD patients. These cells expressed decreased levels of the glucocorticoid receptor (GCR), suggesting their contribution to the steroid resistant property of these cells. COPD is a disease of the small airways. We therefore hypothesized that there would be a further increase in these steroid resistant lymphocytes in the lung, particularly in the small airways. We further hypothesized that the pro-inflammatory/cytotoxic potential of these cells could be negated using prednisolone with low-dose cyclosporin A. Blood, bronchoalveolar lavage, large proximal and small distal airway brushings were collected from 11 COPD patients and 10 healthy aged-matched controls. The cytotoxic mediator granzyme b, pro-inflammatory cytokines IFNγ/TNFα, and GCR were determined in lymphocytes subsets before and after their exposure to 1µM prednisolone and/or 2.5ng/mL cyclosporin A. Particularly in the small airways, COPD subjects showed an increased percentage of CD28null CD8 T-cells and NKT-like cells, with increased expression of granzyme b, IFNγ and TNFα and a loss of GCR, compared with controls. Significant negative correlations between small airway GCR expression and IFNγ/TNFα production by T and NKT-like cells (eg, T-cell IFNγ R= -.834, p=.031) and with FEV (R= -890) were shown. Cyclosporine A and prednisolone synergistically increased GCR expression and inhibited pro-inflammatory cytokine production by CD28null CD8- T and NKT-like cells. COPD is associated with increased pro-inflammatory CD28null CD8+ T and NKT-like cells in the small airways. Treatments that increase GCR in these lymphocyte subsets may improve morbidity in COPD patients.

Objectives We aim to establish daily risk estimates of the relationships between grass, tree and weed pollen and asthma health outcomes.Design Time series regression analysis of exposure and health outcomes using interaction by month to determine risk estimates all year round.Setting Metropolitan Adelaide, South Australia.Participants Health outcomes for asthma are based on 15 years of hospital admissions, 13 years emergency presentations and ambulance callouts. In adults (≥18 years), there were 10 381 hospitalisations, 26 098 emergency department (ED) presentations and 11 799 ambulance callouts and in children (0–17 years), 22 114, 39 813 and 3774, respectively.Outcome measures The cumulative effect of 7 day lags was calculated as the sum of the coefficients and reported as incidence rate ratio (IRR) related to an increase in 10 grains of pollen/m3.Results In relation to grass pollen, children and adults were disparate in their timing of health effects. Asthma outcomes in children were positively related to grass pollen in May, and for adults in October. Positive associations with weed pollen in children was seen from February to May across all health outcomes. For adults, weed pollen-related health outcomes were restricted to February. Adults were not affected by tree pollen, while children’s asthma morbidity was associated with tree pollen in August and September. In children, IRRs ranged from 1.14 (95% CI 1.06 to 1.21) for ED presentations for tree pollen in August to 1.98 (95% CI 1.06 to 3.72) for weed pollen in February. In adults, IRRs ranged from 1.28 (95% CI 1.01 to 1.62) for weed pollen in February to 1.31 (95% CI 1.08 to 1.57) for grass pollen in October.Conclusion Monthly risk assessment indicated that most pollen-related asthma health outcomes in children occur in the colder part of the year, while adults are affected in the warm season. The findings indicate a need for year-round pollen monitoring and related health campaigns to provide effective public health prevention.