The Journal of Association of Chest Physicians

: 2022  |  Volume : 10  |  Issue : 2  |  Page : 75--80

Etiological profile and evaluation of DPLD in real-world: the perceived impression of the ILD treating doctors in India

Parthasarathi Bhattacharyya1, Sikta Mukherjee2, Arindam Mukherjee1, Mintu Paul3, Sayoni Sengupta2, Debkanya Dey2, Ajoy Handa4,  
1 Consultant Pulmonologist, Institute of Pulmocare and Research, Kolkata, India
2 Research Fellow, Institute of Pulmocare and Research, Kolkata, India
3 Research assistant, Institute of Pulmocare and Research, Kolkata, India
4 Consultant Pulmonologist, Bangalore, India

Correspondence Address:
Parthasarathi Bhattacharyya
Institute of Pulmocare and Research, DG-8, New Town, Action Area I, Kolkata - 700 156


Abstract Background The perceived etiologies and the evaluation practice of concerned physicians in the real-world are important for diffuse parenchymal lung disease (DPLD) care. Methods An identified cohort of DPLD treating physicians was given to respond to a set of questions regarding their perception of the relative presence of common etiologies of DPLD in India and also regarding the scope and pattern of evaluation of the condition by them in real-world practice with selective inquiries about the satisfaction and constraints. Results 122 physicians out of 150, mostly (93%) postgraduate and practicing in metropolitan and urban areas (86.07%), participated in the survey. There was the highest abstinence in reply for rare causes of DPLD. As per the highest number/percentage of responses, the perceived etiological distribution for idiopathic pulmonary fibrosis (IPF), non-IPF-ILD (interstitial lung disease), and connective tissue disease-associated ILD was between 11% and 25%, while that of sarcoidosis was 1% to 10 % and chronic hypersensitivity pneumonitis was 26% to 50%. The evaluation habit varied significantly from villages to urban and metropolitan cities. The access to high-resolution computed tomography (HRCT) chest and spirometry was almost universal (98.36%); it dropped to 86.06% and 47.54% for DLCO and multidisciplinary discussions (MDD) (multidisciplinary discussion), respectively. The access to other investigations was variable. The practice of HRCT was universal, but it dropped by 36.30% for spirometry, 67.41% for DLCO, and 62.51% for MDD. The overall satisfaction in evaluation and follow-up was low. Financial and logistic constraints appeared prevalent along with a lack of family support. Conclusion The perceived real-world DPLD practice appears far short of ideal and it needs further investigations to understand the reality to change for betterment.

How to cite this article:
Bhattacharyya P, Mukherjee S, Mukherjee A, Paul M, Sengupta S, Dey D, Handa A. Etiological profile and evaluation of DPLD in real-world: the perceived impression of the ILD treating doctors in India.J Assoc Chest Physicians 2022;10:75-80

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Bhattacharyya P, Mukherjee S, Mukherjee A, Paul M, Sengupta S, Dey D, Handa A. Etiological profile and evaluation of DPLD in real-world: the perceived impression of the ILD treating doctors in India. J Assoc Chest Physicians [serial online] 2022 [cited 2023 Apr 1 ];10:75-80
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Diffuse parenchymal lung disease (DPLD) has emerged as a possible pioneer of humanity’s chronic crippling illnesses for about the last 20 years.[1] In the subcontinent, the diagnosis and understanding of DPLD are growing.

Once regarded as “an orphan disease,” DPLD, as it seems, is not an uncommon problem in clinical practice today across the subcontinent. The entity demands a comprehensive survey in many related areas of concern. Till recently, we had mostly individual center-based information on demography and clinical presentations of DPLD[2],[3],[4],[5],[6],[7],[8],[9] but the prevalence and incidence of DPLD in India are unknown. A recent national registry revealed the relative frequencies of the various etiologies of DPLD in the country.[10]

In this subcontinent, the diagnosis of DPLD has been marred by many issues, and experts have spelled out several deterrent points on this front.[12]Their experience, though genuine, is not scientifically validated. Pending that, it may be worthwhile to understand the real-world related to DPLD diagnosis and treatment. It may help not only to appreciate the lacunae but also to exercise the best possible actions to initiate the desired and directed change to bring forth improvements. Ironically and sadly, while we have access to the same medicines available to the rest of the world, the performance of lung biopsy in DPLD is rare.[13] It reflects the inadequacy in the evaluation of Indian patients. Since appreciation of the deficits as per the perception of the involved physicians in DPLD care can elaborate the situation to a large extent in a quick spell of time, the authors decided for a survey in a cohort of self-identified DPLD treating physicians in India.


Some of the interstitial lung disease (ILD) treating physicians, under the aegis of the Institute of Pulmocare and Research (IPCR), Kolkata, undertook a real-world survey to understand the relative frequency of the etiologies of DPLD according to the perception of ILD treating physicians. The survey also included the pattern of evaluating a DPLD patient in their real world practice of a symposium on the subject (organized by the institute in June 2020). During the discourse, they were primed about the plan and prospective content of such a survey. Accordingly, a list of questions was framed on mutual discussion among the member consultants of the institute and finalized following a selected sample application to a few of our nondoctor members. The survey included the responding physicians’ brief descriptions of qualifications, area of practice (urban, suburban, rural, and metropolitan), domains of practice (pulmonology and mixed), and the region of the country (north, south, east, west) they belong to. The survey also included the perceived range of frequencies for the common etiologies of DPLD. The inquiry also included access to different investigations needed to work up DPLD patients and the actual frequency of using the investigations along with the participating doctors. The survey also included their impression regarding making a prescription without considering constraints such as financial, support or other logistics or the support from their families.

It was a web-based survey using the “survey monkey” platform where the physicians joined voluntarily and responded to the questions placed on them. The perception was noted on the perceived range of frequencies as 10%, <25%, <50%, 75%, and >75% most of the time. The collected data (both parametric and nonparametric) were subsequently analyzed statistically.


The qualifications, practice pattern, area of practice, and the practicing region of the country is elaborated in [Figure 1].{Figure 1}

The percentage of nonresponders vary in frequency for different etiologies as from 11.48% for idiopathic pulmonary fibrosis (IPF) to 27.87% for rare DPLDs [see [Figure 2].{Figure 2}

The different frequency status for different etiologies as perceived by the respondents is shown in [Figure 3].{Figure 3}

A consistent and wide gap is seen between the investigations being used compared to their accessibility [Figure 4].{Figure 4}

The level of satisfaction in the diagnostic workup and follow-up evaluation is elaborated along with the perceived pressure of three important factors as a possible financial burden and other logistic issues are elaborated in [Figure 5].{Figure 5}

The following figure [VIP plot: [Figure 6] shows the access to investigations in different areas such as metropolitan, urban, rural, and suburban. While DLCO, lung biopsy, serological tests, and multidisciplinary discussions (MDD) are most commonly accessed in the metropolitan area, fiber-optic bronchoscopy and collagen profile are most frequently accessed in urban areas. The rural area falls behind the others in respect to the frequency of access for most of the tests.{Figure 6}


The result of the survey is interesting. If the percentage of nonresponders for different etiologies of DPLD is looked at, it is found lowest for IPF (11.46%), high for silicosis (20.49%), and highest for rare DPLDs (27.87%). If this self-declared abstinence from responding suggests a lack of confidence for diagnosis and/or lack of exposure, this relatively low frequency of nonresponders for IPF suggests that most of them have reasonably good confidence for high-resolution computed tomography (HRCT) interpretations of DPLD for detection of classical UIP (usual interstitial pneumonia) pattern.

The number of responders participating to respond to the perceived range of frequency is highest with IPF (n = 94) and lowest (n = 82) with non-IPF-IIPs (idiopathic interstitial pneumonia) [see [Figure 3]. However, the number is similar for sarcoidosis, CVD-ILD, and chronic hypersensitivity pneumonitis (HP) (n = 86, 86, and 88, respectively). If we look at the highest number or percentage of responses for a particular range in perceived frequency of occurrence, 53.49% of responders feel it to be less than 10% for sarcoidosis while 40.91% think that chronic HP constitutes 26% to 50% of the total cases. Similarly, 47.56%, 32.88%, and 48.48% of the responders perceive non-IPF-ILD, IPF, and CVD-ILD, respectively, to prevail between 11% to 25% of the total caseload of DPLD [see [Figure 3]. If we add up the response percentages in the range lying below that with the highest percentage of response, it turns out to be 48.98% for IPF, 64.63% for non-IPF-IIPs, and 73.26% for CVD-ILD to prevail in <25% of perceived occurrence. This figure is 90.89% for chronic HP to remain in a less than 50% occurrence. Interestingly, the perceived prevalence of different etiologies matches to some extent with the results of the ILD-India registry where 47% (below 50%) of the cases belong to chronic HP.[10] Of course, the real-world perception is not comparable to the registry result where the extent of inquiry and investigations were far better than what is done in real-world practice. The observed heterogeneous response distribution in our survey is natural but also reflective of either a) difference in the prevalence of different etiologies in the different parts of the country, b) lack of knowledge or confidence on the part of the responding doctors, or c) the difficulty of a physician to investigate a patient satisfactorily.[11] If the latter is correct, one needs to look into the reasons for it and some of them are already shown [Figure 4]. It also explains the observed gap between the practiced tests and their availability or accessibility.

The evaluation of DPLD is extensive and despite a host of tests being done, the diagnosis is often not forthcoming. This has led to the evolution of MDD (multidisciplinary discussion) that improves the diagnostic efficacy and treatment guidance.[12] Thus, the access to MDD is regarded as an important equivalence of investigation in our inquiry [see [Figure 4]. Thus, access to the HRCT chest is near universal, and the practice of getting it done is similar (98.03%) [Figure 3]. This match in the knowledge and practice is noteworthy and suggests that the participants are aware of the role of HRCT as the most important investigation in a DPLD workup. However, the gap widens markedly as we move from HRCT chest to spirometry to DLCO and subsequently to fiber-optic bronchoscopy and lung biopsy.[13] The difference between the actually accessed and the available investigation (except HRCT chest) is indicative of the possible presence of restraints to practice the other investigations despite knowledge about their roles. It suggests that the HRCT-chest-based initial diagnosis of DPLD is correctly done by almost all, but the further etiological and functional evaluations are grossly deficient in the real-world.[11]

It will be interesting to learn how the physicians interpret the HRCT chest to reach an etiological diagnosis for DPLD[14] with such minimal exercise of evaluation and how far are they correct in their assessment. Moreover, it will be interesting to explore the possibility of improving their performance and satisfaction, both in the short and the long term, by all possible planning and developments. For example, for the diagnosis of chronic HP, the history of exposure to a suspected antigen has the highest odds to support the possibility of HP[15] in DPLD where some HRCT signs are quite indicative of HP.[16] It is noted that roughly two-thirds of the ILD treating doctors avail spirometry and nearly one-third can have DLCO reports to assess the patient. Interestingly, the practice of MDD is found more than that of DLCO and it indicates a healthy trend of using participatory decisions for diagnosis and treatment by the Indian doctors for difficult conditions as DPLD is concerned.

The discrepancies between the accessible and not-accessed tests remain an important issue to address. An understanding of the dynamics of such differences may be attempted from the VIP plot [Figure 6]. As one moves from suburban to urban to metropolitan areas from a rural background, it appears that the practice changes mostly as regards performing different investigations.

While spirometry is practiced equally in all the areas, DLCO, lung biopsy, MDD, bronchoscopy, bronchoalveolar lavage fluid study, and looking for HP-related serology are done most frequently in metropolitan cities and followed by urban areas. However, flexible bronchoscopy and collagen profiles are done more frequently in the urban than the metropolitan areas. This could be a reflection of an effort to overcome the constraints to get those available in the metropolitan areas. The status of access to evaluations is poorest in the rural areas and is slightly better in suburban areas.

Spirometry seems most commonly done after HRCT chest. It, along with the serological tests, is essentially laboratory-based investigations that are more widely available than the other tests such as DLCO, MDD, lung biopsy, and bronchoscopy. The latter list is more related to the availability of the establishment of infrastructures and the availability of related expertise.

In India, the availability for investigations has penetrated or developed far higher than the development of a little sophisticated health care infrastructure establishments and the availability of expertise targeting DPLD evaluation. The corporate investigation centers have expanded enormously in the country over the last two decades having their collection centers in smaller towns with efficient cryo-transport of the biological samples.[17] This makes the blood and sophisticated serological tests available across the urban and may be many selected suburban areas. However, the demand for expertise and the necessary infrastructure possibly makes it difficult for the invasive and little sophisticated tests to be available peripherally. This explains the low rate of bronchoscopy or bronchoalveolar lavage fluid analysis and even the measurement of the diffusion capacity as one moves out from metropolis to urban to suburban and rural areas as is apparent in the VIP plot [Figure 6]. The low prevalence of the practice of multidisciplinary discussion (MDD) as14.75%, referral to an expert (4.92%), or seeking a second opinion (5.74%) may have an association with this dearth of appropriate manpower. The lung transplantation centers in the country are only handful in number.[18] They all may contribute to AQ10 the poor level of satisfaction in the evaluation and follow up (22.57 and 25.0 as a mean percentage, respectively) of the DPLD subjects. Therefore, it is unlikely the dearth of knowledge but the adverse ground reality that holds back the physicians to practice the ideal.

To understand the ground reality or the logistic constraints, we looked at the perception of the treating physicians of the country as the easiest available source for an approximate idea of the real-world [Figure 5]. If more than 75% availability or degree of access is measured as satisfactory, this degree of treatment satisfaction is there in only 27.11% of doctors and the follow-up satisfaction to a similar degree falls to 19.0% for them [see [Figure 6]. With the same criteria of over 75% availability of funds and family support, only 6.8% of the doctors treating DPLD can make a prescription without considering financial burden or any logistic constraint. To their perception, adequate family support is available to such a satisfactory degree to the tune of only 18.85%. There are significant constraints related to financial or other logistic limitations as is apparent that only 24.95% of our doctors can afford to prescribe without considering the economic burden. In India, family support appears important as health care is not a state responsibility and the penetration of medical insurance is yet inadequate. In addition, there is a psychological component to it. The perceived family support to the patients is found inadequate in three-fourths of the cases. This comes as a supplementary to our findings on the logistic constraints for treating DPLD in the country.

There are several important limitations of the study. The number of respondents is small with heterogeneous representation from the different parts of the country (more from the eastern zone). Moreover, the respondents are a select group as primarily self-motivated DPLD treating physicians. Both these factors may play an influence in understanding the actual real-world situation. The inquiries are limited to a selected area of perception and the planned depth of investigation was kept intentionally relatively shallow. However, in face of no information in the literature on this important issue, we feel that even this bit of information can act as an eye-opening effort to understand the reality where the logistic constraint plays a major role in the suboptimal care of DPLD in the country.[11] We have no idea about the dearth of appropriate manpower for this study. Furthermore, it is not possible from the survey to speak anything about the overall quality of the involved manpower in DPLD care. However, the selective population joining the survey (DPLD treating doctors) seems to have reasonable knowledge to evaluate a case of DPLD. We need much more operational research to understand the reality in-depth to plan and act to mitigate the deficiencies.

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Conflicts of interest

There are no conflicts of interest.


1Rivera-Ortega P, Molina-Molina M. Interstitial lung diseases in developing countries. Ann of Glob Health 2019;85:1–14.
2Kumar MS. Clinical study on interstitial lung diseases in a tertiary teaching hospital of North Kerala. Int J Sci Study 2017;5:65–70.
3Valappil AT, Mehta AA, Kunoor A, Haridas N. Spectrum of diffuse parenchymal lung diseases: an experience from a tertiary care referral centre from South India. Egypt J Chest Dis Tuberc 2018;67:276–280.
4Jindal SK, Sharma BK. Fibrosing alveolitis: a report of 61 cases seen over the past five years. Indian J Chest Dis Allied Sci 1979;21:174–9.Mahashur AA, KM, , , , . . Lung India 1983;1:171-179.
5Mahashur AA, Dave KM, Kinare SG, Kamat SR, Shetye VM, Kolhatkar VP Diffuse fibrosing alveolitis-an Indian experience. Lung India 1983;1:171–179.
6Sharma SK, Guleria JS. Bronchoalveolar lavage fluid (BALF) analysis in interstitial lung diseases--a 7-year experience. Indian J Chest Dis Allied Sci 1989;31:187–96.
7Maheshwari U, Jindal SK. Spectrum and diagnosis of idiopathic pulmonary fibrosis. Indian J Chest Dis Allied Sci 2004;46:23–6.
8Subhash HS, Ashwin I, Solomon SK, David T, Cherian AM, Thomas K. A comparative study on idiopathic pulmonary fibrosis and secondary diffuse parenchymal lung disease. Indian J of Med Sci 2004;58:185–90.
9Sen T, Udwadia ZF. Retrospective study of interstitial lung disease in a tertiary care centre in India. Indian J Chest Dis Allied Sci 2010;52:207–211.
10Singh S, Collins BF, Sharma BB, Joshi JM, Talwar D, Katiyar S, Singh N, Ho L, Samaria GK, Bhattacharya P, Gupta R. Interstitial lung disease in India. Results of a prospective registry. Am J Respir Crit Care Med 2017;195:801–13.
11Udwadia ZF, Jindal SK. Interstitial lung diseases in a resource-limited setting: the case of India. Eur Respir Monogr 2009;46:357–74.
12Ageely G, Souza C, De Boer K, Zahra S, Gomes M, Voduc N. The impact of multidisciplinary discussion (MDD) in the diagnosis and management of fibrotic interstitial lung diseases. Can Respir J 2020 2020;1–6.
13Sigurdsson MI, Gudbjartsson T. Diagnostic surgical lung biopsies for suspected interstitial lung diseases: a retrospective study. Ann Thorac Surg 2009;88:227–32.
14Flaherty KR, Gay SE. Idiopathic interstitial pneumonia: do community and academic physicians agree on diagnosis? Am J Respir Crit Care Med 2007;175:1054–60.
15Lacasse Y, Cormier Y. Clinical diagnosis of hypersensitivity pneumonitis. Am J Respir Crit Care Med 2003;168:952–8.
16Lima MS, Pereira CA. Subacute and chronic hypersensitivity pneumonitis: histopathological patterns and survival. Respiratory medicine 2009;103:508–15.
17Dash S, Kaushik S. Big data in healthcare: management, analysis and future prospects. J Big Data 2019;6:1–25.
18Shah UB, Attawar S. Challenges of lung transplantation in India. Indian J Thorac Cardiovasc Surg 2021;24:1–8.