Epidemiology Of Interstitial Lung Disease Research Articles

Prevalence, incidence, and survival analysis of interstitial lung diseases in Hong Kong: a 16-year population-based cohort study

Published data on the epidemiology of interstitial lung disease (ILD) in Asia is scarce. Understanding the epidemiology is important for authorities in the health management planning. This study aimed to estimate the prevalence, incidence, and survival of ILD in Hong Kong from 2005 to 2020 and evaluate the change of trend over time. In this retrospective cohort study, we identified ILD patients between 2005 and 2020 using a territory-wide electronic health record database. Prevalence, incidence rates, and age- and sex-standardised incidence rates with United Nations population in 2020 as a reference were estimated. Trends in prevalence and incidence were analysed using joinpoint regression and the average annual percent change (AAPC) was estimated. Median survival, and risk factors of mortality were evaluated using Cox proportional hazard regression. We identified 5924 patients and included 5884 of them for analysis. The prevalence of ILD increased from 24.7 to 33.6 per 100,000 population from 2005 to 2020 with an AAPC of 1.94 (95% confidence interval, CI: 1.69-2.34). The standardized incidence rate decreased from 5.36 to 2.57 per 100,000 person from 2005 to 2020 (AAPC-3.56, 95% CI,-4.95 to-1.78). The median survival of ILD was 2.50 (95% CI, 2.32-2.69) years. Male, older age, higher Charlson comorbidity index, and IIP subtype were associated with increased mortality with statistical significance. This study provided the first epidemiological evaluation of ILD in Hong Kong. Further studies on ILD in multiple Asian cities and countries are warranted. None.

Epidemiology of interstitial lung disease in patients with metastatic breast cancer at baseline and after treatment with HER2-directed therapy: a real-world data analysis

PurposeUsing real-world data, interstitial lung disease (ILD) prevalence before and after HER2-directed therapy was estimated. Potential ILD risk factors in patients receiving HER2-directed therapy for metastatic breast cancer (mBC) were evaluated.MethodsAdults with HER2-directed therapy for mBC initiated between September 25, 1998, and February 22, 2020 were, included. ILD was defined broadly as one or more of 64 lung conditions. Patients were followed until incident ILD, death, last contact, or study end.ResultsIn total, 533 patients were identified with median age at mBC of 57, 51% had de novo mBC, 43% were ever smokers, 30% had lung metastases, 9% had thoracic radiation, 6% had chronic obstructive pulmonary disease, and 16% had prevalent ILD. ILD cumulative incidence at one year was 9% (95% CI 6%, 12%), with a median follow-up of 23 months. Smoking (HR 2.2, 95% CI 1.1, 4.8) and Black/African-American race (HR 3.4, 95% CI 1.6, 7.5) were significantly associated with ILD; HRs for preexisting lung conditions (HR 1.8, 95% CI 0.9, 3.8) and thoracic radiation (HR 2.3, 95% CI 0.8, 7.1) were not statistically significant. Prevalent ILD was associated with 13-fold greater occurrence of incident ILD. 85% of patients with prevalent or incident ILD were symptomatic.ConclusionsThis real-world population of patients with mBC had a high prevalence of ILD prior to HER2-directed therapy, reflecting the multifactorial causation of interstitial lung changes. The cumulative incidence of ILD in patients receiving HER2-directed therapy for mBC augments prior reports. Symptomatic presentation suggests an opportunity for early intervention.

Incidence, prevalence, and national burden of interstitial lung diseases in India: Estimates from two studies of 3089 subjects.

Background and objectiveThe epidemiology of interstitial lung diseases (ILDs) in developing countries remains unknown. The objective of this study was to estimate the incidence, prevalence, and national burden of ILDs in India.MethodsData of consecutive subjects (aged >12 years) with ILDs included in a registry between March 2015 and February 2020 were analyzed retrospectively. The proportion of each ILD subtype was determined. The crude annual incidence and prevalence of ILDs for our region were estimated. Subsequently, the primary estimates of the national annual incident and prevalent burden of ILD and its subtypes were calculated. Alternative estimates for each ILD subtype were calculated using the current and a large, previous Indian study (n = 1,084). Data were analyzed using SPSS version 22 and are presented descriptively.ResultsA total of 2,005 subjects (mean age, 50.7 years; 47% men) were enrolled. Sarcoidosis (37.3%) was the most common ILD subtype followed by connective tissue disease (CTD)-related ILDs (19.3%), idiopathic pulmonary fibrosis (IPF, 17.0%), and hypersensitivity pneumonitis (HP, 14.4%). The crude annual incidence and prevalence of ILDs were 10.1–20.2 and 49.0–98.1, respectively per 100,000 population. The best primary estimates for the crude national burden of all ILDs, sarcoidosis, CTD-ILD, IPF, HP, and other ILDs (in thousands) were 433–867, 213–427, 75–150, 51–102, 54–109, and 39–78. The respective alternative estimates (in thousands) were sarcoidosis, 127–254; CTD-ILD, 81–162; IPF, 46–91; HP, 130–261; other ILDs, 49–98.ConclusionIn contrast to developed countries, sarcoidosis and HP are the ILDs with the highest burden in India.

Epidemiology of interstitial lung disease in systemic lupus erythematosus in France: A nation-wide population-based study over 10 years.

Background and objectiveData regarding interstitial lung disease (ILD) in the setting of systemic lupus erythematosus (SLE) are limited. We used a nationwide database to determine the incidence and the prevalence of ILD in SLE.MethodsCharacteristics of all SLE inpatients admitted between 2011 and 2012 in France were analysed through the French medico‐administrative database. Features associated with the presence of ILD were studied. Cox hazard model was used to measure the impact of ILD on survival from the first stay to 2020. The incidence of ILD in SLE was estimated by analysing the onset of ILD from 2013 to 2020 in SLE patients who had no evidence of ILD in 2013.ResultsBetween 2011 and 2012, 10,460 SLE patients had at least one hospital stay and could be traced until 2020. Among them, 134 (1.2%) had an ILD diagnosed at baseline. The frequency of ILD in SLE was higher in patients who had an associated autoimmune disease such as Sjögren's syndrome or systemic sclerosis (29.9% vs. 5.9%, p < 0.0001). ILD was associated with an increased risk of death in SLE in the multivariable analysis (hazard ratio [95% CI] 1.992 [1.420–2.794]; p < 0.0001). Among the 31,029 SLE patients with no evidence of ILD at baseline, ILD occurred in 795 (2.6%) between 2013 and 2020. The incidence rate of ILD in SLE was 10.26 for 1000 patient‐years [95% CI: 10.24–10.28].ConclusionIn SLE, ILD is exceedingly rare, often associated with another systemic autoimmune disorder and appears as a major risk factor for death.

ERS International Congress 2021: highlights from the Paediatric Assembly.

In this review, Early Career Members of the European Respiratory Society (ERS) and the Chairs of the ERS Assembly 7: Paediatrics present the highlights in paediatric respiratory medicine from the ERS International Congress 2021. The eight scientific Groups of this Assembly cover respiratory physiology and sleep, asthma and allergy, cystic fibrosis (CF), respiratory infection and immunology, neonatology and intensive care, respiratory epidemiology, bronchology, and lung and airway development. We here describe new developments in lung function testing and sleep-disordered breathing diagnosis, early life exposures affecting pulmonary function in children and effect of COVID-19 on sleep and lung function. In paediatric asthma, we present the important role of the exposome in asthma development, and how biologics can provide better outcomes. We discuss new methods to assess distal airways in children with CF, as some details remain blind when using the lung clearance index. Moreover, we summarise the new ERS guidelines for bronchiectasis management in children and adolescents. We present interventions to reduce morbidity and monitor pulmonary function in newborns at risk of bronchopulmonary dysplasia and long-term chronic respiratory morbidity of this disease. In respiratory epidemiology, we characterise primary ciliary dyskinesia, identify early life determinants of respiratory health and describe the effect of COVID-19 preventive measures on respiratory symptoms. Also, we describe the epidemiology of interstitial lung diseases, possible consequences of tracheomalacia and a classification of diffuse alveolar haemorrhage in children. Finally, we highlight that the characterisation of genes and pathways involved in the development of a disease is essential to identify new biomarkers and therapeutic targets.

Epidemiology of interstitial lung diseases and their progressive-fibrosing behaviour in six European countries.

The PERSEIDS study aimed to estimate incidence/prevalence of interstitial lung diseases (ILDs), fibrosing interstitial lung diseases (F-ILDs), idiopathic pulmonary fibrosis (IPF), systemic sclerosis-associated ILD (SSc-ILD), other non-IPF F-ILDs and their progressive-fibrosing (PF) forms in six European countries, as current data are scarce.This retrospective, two-phase study used aggregate data (2014–2018). In Phase 1, incident/prevalent cases of ILDs above were identified from clinical databases through an algorithm based on codes/keywords, and incidence/prevalence was estimated. For non-IPF F-ILDs, the relative percentage of subtypes was also determined. In Phase 2, a subset of non-IPF F-ILD cases was manually reviewed to determine the percentage of PF behaviour and usual interstitial pneumonia-like (UIP-like) pattern. A weighted mean percentage of progression was calculated for each country and used to extrapolate incidence/prevalence of progressive-fibrosing ILDs (PF-ILDs).In 2018, incidence/105 person-years ranged between 9.4 and 83.6 (ILDs), 7.7 and 76.2 (F-ILDs), 0.4 and 10.3 (IPF), 6.6 and 71.7 (non-IPF F-ILDs), and 0.3 and 1.5 (SSc-ILD); and prevalence/105 persons ranged between 33.6 and 247.4 (ILDs), 26.7 and 236.8 (F-ILDs), 2.8 and 31.0 (IPF), 22.3 and 205.8 (non-IPF F-ILDs), and 1.4 and 10.1 (SSc-ILD). Among non-IPF F-ILDs, sarcoidosis was the most frequent subtype. PF behaviour and UIP-like pattern were present in a third of non-IPF F-ILD cases each and hypersensitivity pneumonitis showed the highest percentage of progressive behaviour. Incidence of PF-ILDs ranged between 2.1 and 14.5/105 person-years, and prevalence between 6.9 and 78.0/105 persons.To our knowledge, PERSEIDS is the first study assessing incidence, prevalence and rate of progression of ILDs across several European countries. Still below the threshold for orphan diseases, the estimates obtained were higher and more variable than reported in previous studies, but differences in study design/population must be considered.

Incidence, prevalence and long-term progression of Goh algorithm rated interstitial lung disease in systemic sclerosis in two independent cohorts in flanders: A retrospective cohort study

Objectives: The epidemiology of interstitial lung disease (ILD) in systemic sclerosis (SSc) in Belgium is unknown. In literature, its prevalence varies between 19% and 52% in limited/diffuse cutaneous SSc (LcSSc/DcSSc). However, its prevalence in “early” SSc (pre-clinically overt SSc without [yet] skin involvement), nor its incidence rate in SSc (LcSSc/DcSSc/“early” SSc) has ever been described. Against this background, we aimed to determine the prevalence/incidence (rate) and progression of ILD in SSc.Methods: 12-year follow-up data of consecutive SSc patients, included in two Flemish cohorts (University Hospitals Ghent and Leuven), were retrospectively analysed. ILD was classified according to the simplified Goh algorithm. Progression of ILD was defined as a relative decline of FVC ≥10%, a combined relative decline of FVC 5-10% and DLCO ≥15%, or as an increase in HRCT extent.Results: 722 patients (60% LcSSc/ 20% DcSSc/ 20% “early” SSc, median (IQR) follow-up 39 [12-80] months) had baseline HRCT. 243 were rated to have ILD at baseline and 39 during follow-up (prevalence of 34%/ incidence rate of 20.3/1000PY, 95%CI:14.5-27.8). Amongst those with baseline ILD, 60% had lung functional progression at five years of follow-up. In the “early” SSc subgroup, eight patients were rated to have ILD at baseline and three during follow-up (prevalence of 6%/ incidence rate of 5.8/1000 PY, 95%CI:1.2-17.0).Conclusion: Both LcSSc and DcSSc patients should be monitored for ILD evolution. The low prevalence and incidence of ILD in the “early” SSc subgroup may instruct future decisions on the construction of uniform patient follow-up pathways in “early” SSc.

Interstitial lung disease in a veterans affairs regional network; a retrospective cohort study.

The epidemiology of Interstitial Lung Diseases (ILD) in the Veterans Health Administration (VHA) is presently unknown. Describe the incidence/prevalence, clinical characteristics, and outcomes of ILD patients within the Veteran's Administration Mid-Atlantic Health Care Network (VISN6). A multi-center retrospective cohort study was performed of veterans receiving hospital or outpatient ILD care from January 1, 2008 to December 31st, 2015 in six VISN6 facilities. Patients were identified by at least one visit encounter with a 515, 516, or other ILD ICD-9 code. Demographic and clinical characteristics were summarized using median, 25th and 75th percentile for continuous variables and count/percentage for categorical variables. Characteristics and incidence/prevalence rates were summarized, and stratified by ILD ICD-9 code. Kaplan Meier curves were generated to define overall survival. 3293 subjects met the inclusion criteria. 879 subjects (26%) had no evidence of ILD following manual medical record review. Overall estimated prevalence in verified ILD subjects was 256 per 100,000 people with a mean incidence across the years of 70 per 100,000 person-years (0.07%). The prevalence and mean incidence when focusing on people with an ILD diagnostic code who had a HRCT scan or a bronchoscopic or surgical lung biopsy was 237 per 100,000 people (0.237%) and 63 per 100,000 person-years respectively (0.063%). The median survival was 76.9 months for 515 codes, 103.4 months for 516 codes, and 83.6 months for 516.31. This retrospective cohort study defines high ILD incidence/prevalence within the VA. Therefore, ILD is an important VA health concern.

Incidence and Disease Burden of Interstitial Lung Disease and Pulmonary Sarcoidosis from 1990 to 2019: Results from the Global Burden of Disease Study 2019

Background: Interstitial lung disease (ILD) and pulmonary sarcoidosis are common respiratory disease with a heterogeneous distribution worldwide. In present study, we aimed to characterize the global disease burden of ILD and pulmonary sarcoidosis using data from the Global Burden of Disease Study 2019 (GBD2019). Methods: Crude and age-standardized rates (ASRs) of incidence, mortality, and DALYs for ILD and pulmonary sarcoidosis were obtained from GBD 2019. We used GBD methodology to systematically analyze the temporal and geographical trends of ILD and pulmonary sarcoidosis in 204 countries and territories from 1990 to 2019, by sex, socio-demographic index (SDI), and region. Findings: In 2019, the global incident cases due to ILD and pulmonary sarcoidosis was 24,232,080 (95% UI, 19,609,750 ~ 29,463,387), mortality case due to ILD and pulmonary sarcoidosis was 169,833 (95% UI, 118,756 ~204,802). From 1990 to 2019, the incident, death, and DALYs case number of ILD and pulmonary sarcoidosis increased by 118·6%, 166·63%, and 122·87% respectively. The global incidence of ILD and pulmonary sarcoidosis was higher in males, and it was mainly concentrated in the age group of 70~79 years in both sexes. Significant regional differences can be seen in the incidence of ILD and pulmonary sarcoidosis. Interpretation: Our study shows that the ASRs of incidence, mortality, and DALYs for ILD and pulmonary sarcoidosis are increasing. And considerable heterogeneity in the epidemiology of ILD and pulmonary sarcoidosis across age, sex, and region can be seen, great efforts are warranted to reduce the disease burden of ILD. Funding Statement: This study was financially supported by Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences [No: 2018-12M-1-001], Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences [No. 2019PT320021], the National Natural Science Foundation of China [No:81870056]. Declaration of Interests: The writing committee declares no competing interests. Ethics Approval Statement: This study used data from GBD 2019. Access to and use of GHDx data did not require informed patient consent.

Characteristics of Chronic Cough in adults in Pakistani population: A cross sectional study.

Background and Objective:Data about causes of chronic cough are lacking in our part of world. The aim of our study was to look for spectrum of causes in our setup and to determine a correlation between causes of cough and baseline factors of age, gender, and BMI and compare it to other populations.Methods:Total 236 chronic cough patients who attended chest clinic at KRL Hospital Islamabad from January 2018 to June 2019 were included in this cross-sectional study. Chronic cough was defined as cough greater than eight weeks. Main causes of chronic cough taken were cough variant asthma, allergic rhinitis, interstitial lung disease, Gastro-esophageal reflux disease, bronchial hyper-reactivity, ACE-I induced cough and others’. Other demographic and clinical data were also recorded.Results:The mean age was 45.16± 16.50 years and BMI was 26.23 ± 4.68kg/m2. Major cause of chronic cough was cough variant asthma in 111(47%). Age had significant positive correlations with ILD, ACE-I induced cough and CCF, while significant negative correlations with CVA and AR. On gender correlation, ILD and ACE-I cough were significantly found more in females. BMI had significant correlation with ACE-I cough only.Conclusion:Variability of epidemiology of cough variant asthma, allergic rhinitis and ACE-I induced cough is comparable to worldwide data while differences exist with epidemiology of interstitial lung disease. Further research is needed in the field to delineate the local trends in this regard and compare to other population groups.

Powers and Pitfalls of Using Administrative Data to Study the Epidemiology of Interstitial Lung Diseases

Powers and Pitfalls of Using Administrative Data to Study the Epidemiology of Interstitial Lung Diseases

Estimating the incidence of interstitial lung diseases in the Cree of Eeyou Istchee, northern Québec.

BackgroundLittle is known about the epidemiology of interstitial lung disease (ILD) amongst Canada’s Indigenous populations. Clinicians working in Eeyou Istchee (the Cree territory of the James Bay region of Québec, population 17, 956) suspected that ILD was more common in this area. We sought to identify all prevalent and incident cases of ILD in Eeyou Istchee between 2006 and 2013, to describe characteristics of affected patients, distribution of subtypes, and estimate disease incidence.MethodsPotential ILD cases amongst Eeyou Istchee residents were identified by searching hospitalization databases and lists of patients on long term home oxygen in the region’s nine communities, and surveying physicians and nurses. Clinical, radiological and pathological data were reviewed. Potential cases were classified as ‘Definite ILD’ if an open lung biopsy demonstrated ILD or, in the absence of histopathologic confirmation, if their thoracic CT imaging was deemed consistent with ILD by a panel of two respirologists and a chest radiologist. Potential cases for whom CT images could not be retrieved for our review were not eligible for classification as Definite ILD, unless they had undergone open lung biopsy. The Definite ILD group was further categorized by subtype of ILD. For usual interstitial pneumonia and non-specific interstitial pneumonitis patterns, we assumed cases were idiopathic in the absence of documentation of connective tissue disease or occupational exposures in the medical chart. For Definite ILD and the most common subtype, we calculated the average annual incidence rates, age-standardized to the province of Quebec, for 2006 to 2013, using a gamma distribution to calculate 95% confidence intervals.ResultsOf 167 potential cases, 52 were categorized as Definite ILD: 14 on the basis of histopathology and 38 on the basis of CT imaging alone. Six patients had a prior history of connective tissue disease. Information on occupation was recorded in the charts of 18/52 (35%) cases, and missing in the remainder. We found the most common subtype was idiopathic pulmonary fibrosis (27/52, 52%), followed by idiopathic non-specific interstitial pneumonia (13/52, 25%), and secondary usual interstitial pneumonia associated with connective tissue diseases (5/52, 10%). The age-standardized annual incidence between 2006–2013 was 80 per 100,000 person-years observed (PYO) for ILD, and 46 per 100,000 PYO for idiopathic pulmonary fibrosis.InterpretationThe incidence of ILD and of idiopathic pulmonary fibrosis in Eeyou Istchee may be higher than rates reported in other populations; however, cautious interpretation is required due to the lack of histopathological confirmation in the majority of cases, and our reliance on chart review to exclude secondary causes. A prospective study of incident cases with standardized assessments to establish the types of ILD and to assess for potential causes could overcome some of the limitations of the present analysis. Studies evaluating ILD incidence and subtype distribution in other Indigenous populations would also be of interest.

Epidemiology of interstitial lung disease in Palestine: first national data

Significant progress has been made in recent years in understanding the epidemiology of interstitial lung diseases (ILD) across the world, but the amount of information available is still small compared to other respiratory diseases like obstructive lung diseases or lung cancer. In this study we tried to explore the epidemiology of ILD in a virgin area of the world (Palestine), by describing a retrospectively collected cohort of newly diagnosed ILD cases in a single – and the only – Pulmonology center in Palestine over two years.

Epidemiology of interstitial lung disease in Palestine: first national data

Significant progress has been made in recent years in understanding the epidemiology of interstitial lung diseases (ILD) across the world, but the amount of information available is still small compared to other respiratory diseases like obstructive lung diseases or lung cancer. In this study we tried to explore the epidemiology of ILD in a virgin area of the world (Palestine), by describing a retrospectively collected cohort of newly diagnosed ILD cases in a single – and the only – Pulmonology center in Palestine over two years.

Interstitial Lung Disease in the Elderly

Despite the relationship between idiopathic pulmonary fibrosis (IPF) and advancing age, little is known about the epidemiology of interstitial lung disease (ILD) in the elderly. We describe the diagnoses, clinical characteristics, and outcomes of patients who were elderly at the time of ILD diagnosis. Among subjects from a prospective cohort study of ILD, elderly was defined as age≥ 70 years. Diagnoses were derived from a multidisciplinary review. Differences between elderly and nonelderly groups were determined using the χ2 test and analysis of variance. Of the 327 subjects enrolled, 80 (24%) were elderly. The majority of elderly subjects were white men. The most common diagnoses were unclassifiable ILD (45%), IPF (34%), connective tissue disease (CTD)-ILD (11%), and hypersensitivity pneumonitis (8%). Most elderly subjects (74%) with unclassifiable ILD had an imaging pattern inconsistent with usual interstitial pneumonia (UIP). There were no significant differences in pulmonary function or 3-year mortality between nonelderly and elderly subjects combined or in a subgroup analysis of those with IPF. Although IPF was the single most common diagnosis, the majority of elderly subjects had non-IPF ILD. Our findings highlight the need for every patient with new-onset ILD, regardless of age, to be surveyed for exposures and findings of CTD. Unclassifiable ILD was common among the elderly, but for most, the radiographic pattern was inconsistent with UIP. Although the effect of ILD may be more pronounced in the elderly due to reduced global functionality, ILD was not more severe or aggressive in this group.

Exploring Clinical and Epidemiological Characteristics of Interstitial Lung Diseases: Rationale, Aims, and Design of a Nationwide Prospective Registry--The EXCITING-ILD Registry.

Despite a number of prospective registries conducted in past years, the current epidemiology of interstitial lung diseases (ILD) is still not well defined, particularly regarding the prevalence and incidence, their management, healthcare utilisation needs, and healthcare-associated costs. To address these issues in Germany, a new prospective ILD registry, “Exploring Clinical and Epidemiological Characteristics of Interstitial Lung Diseases” (EXCITING-ILD), is being conducted by the German Centre for Lung Research in association with ambulatory, inpatient, scientific pulmonology organisations and patient support groups. This multicentre, noninterventional, prospective, and observational ILD registry aims to collect comprehensive and validated data from all healthcare institutions on the incidence, prevalence, characteristics, management, and outcomes regarding all ILD presentations in the real-world setting. Specifically, this registry will collect demographic data, disease-related data such as ILD subtype, treatments, diagnostic procedures (e.g., HRCT, surgical lung biopsy), risk factors (e.g., familial ILD), significant comorbidities, ILD managements, and disease outcomes as well as healthcare resource consumption. The EXCITING-ILD registry will include in-patient and out-patient ILD healthcare facilities in more than 100 sites. In summary, this registry will document comprehensive and current epidemiological data as well as important health economic data for ILDs in Germany.

Spectrum of interstitial lung disease at a tertiary care centre in India.

The available data on the epidemiology of interstitial lung disease (ILD) from India is sparse. Hence, the present study was undertaken with the aim to analyse the demographic profile and clinical, radiological and pathological characteristics along with physiological parameters of various subgroups of ILD patients. We retrospectively studied 289 patients diagnosed with ILD during the years 2001-2013 at one of the respiratory units of Vallabhbhai Patel Chest Institute. Mean age at presentation was 44.24 years; females comprised 54.68% of the patients. Prior to presentation at our centre, 14.84% patients had been treated with antituberculous therapy due to misdiagnosis of tuberculosis. In the pool of ILDs analysed, sarcoidosis (37.3%) was found to be the most common subgroup, followed by IPF (27.6%) and NSIP (25.6%). Cough (92.97%) was the most common presenting symptom; exertional dyspnoea was found in 79.2% of patients. Digital clubbing was commonest in IPF, found in 30% of patients. Significant desaturation on six-minute walk test was most frequenty seen (50%) in NSIP patients. The most common pattern on chest roentgenogram was reticular/reticulo-nodular pattern (80.2%) and on HRCT - interstitial fibrosis (49.9%). Mean of predicted total lung capacity (TLC) was 64.3%, the lowest being in the IPF group (58.88%). Mean of predicted DLCO was 50.56%, the lowest being in the IPF group (42.75%). The overall diagnostic yield of bronchoscopic biopsy was 83.04%, the highest yield being among sarcoidosis patients (96.29%). We found sarcoidosis, IPF and NSIP to be the most common ILDs in northern India. ILDs are still frequently misdiagnosed as TB, and increased awareness, education and diagnostic facilities are required to diagnose ILDs at an early stage.

Epidemiology of interstitial lung diseases in Greece

Few data are available on the epidemiology of interstitial lung diseases (ILDs), especially after the current classification of idiopathic interstitial pneumonias. The aim of this study is to provide data on the epidemiology of ILDs in Greece, under the ATS/ERS international consensus. Departments of Pneumonology were contacted and asked to complete a questionnaire for every case of ILD that was alive on 2004 as well as for every new case from 1st January 2004 to 31st December 2004. Questions on the patients' demographic data, the exact diagnosis and the procedures used to establish the diagnosis were included. Centers covering about 60% of the Greek population have been analyzed. A total of 967 cases have been registered. The estimated prevalence of ILDs is 17.3 cases per 100,000 inhabitants. The estimated annual incidence of ILDs is 4.63 new cases per 100,000 inhabitants. The most frequent disease is sarcoidosis (34.1%), followed in decreasing order by idiopathic pulmonary fibrosis (19.5%), ILD associated with collagen vascular diseases (12.4%), cryptogenic organizing pneumonia (5.3%), histiocytosis (3.8%), and hypersensitivity pneumonitis (2.6%). Unclassified ILD or not otherwise specified accounted for the 8.5% of prevalent cases. These data suggest that sarcoidosis and idiopathic pulmonary fibrosis are the most frequent ILDs in our population. In comparison with the few previous reports, interesting dissimilarities have been observed.

The epidemiology of interstitial lung disease and its association with lung cancer.

The criteria and terminology for diagnosing interstitial lung disease (ILD), a diverse range of pulmonary fibrotic disorders that affect the alveoli of the lungs, have been variable and confusing; however, there have been recent major improvements to an internationally agreed classification. Evidence from recent analyses of populations suggests that the incidence and prevalence rates of ILD are on the increase, particularly when the broad definition of ILD is used. In most patients with ILD a cause is not identified; nevertheless, among the established causes are a number of drug therapies and infections. Occupational causes are lessening in importance, while cigarette smoking is now an established risk factor. Radiation therapy for cancer is a well-established cause of ILD that usually, but not always, localises within the radiation portal and may occur later after completion of therapy. Similarly, exposure to drugs long after radiation therapy may be an aetiological factor for the development of ILD later in life, although the magnitude of this risk requires further epidemiological investigation. The possibility that ILD and lung cancer are associated has been recognised for >50 years, but it remains unclear whether ILD precedes lung cancer or vice versa. In this review, we examine the epidemiology of ILD and the basis for its association with lung cancer.

The epidemiology of interstitial lung diseases.

Little epidemiologic data are available on the occurrence of interstitial lung diseases (ILDs) in the general population. To describe the prevalence and incidence of ILDs a population-based registry of patients with ILDs was established in Bernalillo County, New Mexico in October 1988. All patients 18 yr of age and older who had a clinical diagnosis of an ILD were identified during the period 10/1/88 through 9/30/90 from physician referrals, hospital discharge diagnoses, histopathology reports, and death certificates. In addition, the prevalence of preclinical or undiagnosed cases was identified by screening lung specimens from 510 autopsy cases. A total of 2,936 referrals were screened; 8.8% were prevalent cases and 6.9% were incident cases. Overall, the prevalence of ILDs was 20% higher in males (80.9 per 100,000) than in females (67.2 per 100,000). Similarly the overall incidence of ILDs was slightly more common in males (31.5 per 100,000/year) than females (26.1 per 100,000/year). The estimated prevalence of preclinical or undiagnosed ILDs among all deaths was 1.8%. The most common incident diagnosed among both sexes were pulmonary fibrosis and idiopathic pulmonary fibrosis, together accounting for 46.2% of all ILD diagnoses in males and 44.2% in females. We conclude that the occurrence of ILDs in the general population may be more common than previous estimates based on selected populations, and these disorders may frequently be unrecognized.