Study design and population
An observational study was conducted on all individuals screened by either of the two case finding strategies using a mobile x-ray unit (MXU) in District Mewat, Haryana during January 2016 to March 2016.
General setting
The study was carried out in District Mewat, one of the 22 districts of Haryana state in Northern India inhabited by nearly 1.08 million people. Majority (95%) of the population lives in rural areas. It has a sex ratio of 906 females for every 1000 males and a literacy rate of 56.1% [7]. The district has 33 public health facilities including 01 District Hospital, 03 Community Health Centres (CHCs), 06 Primary Health Centres (PHCs) and 23 Sub-centres (SCs) [8].
Specific setting
Medanta the Medicity, a corporate hospital in Gurgaon in collaboration with the Government of Haryana launched the “TB Free Haryana” campaign. A key strategy was of this campaign was identification of missing TB cases in the rural remote communities and put them to appropriate care. A mobile van equipped with a digital CXR machine visited a government health facility every week. An x-ray technician, nurse and a driver accompanied the van. Two strategies of active case finding were employed using a “health camp approach”.
Strategy 1: Four peripheral health facilities were visited during Jan and Feb 2016. The medical officer of the health facility was informed in advance of the arrival of the mobile van. Adult patients (18 years and above) who, according to the Revised National Tuberculosis Control Programme (RNTCP) diagnostic algorithm were eligible but not able to get a CXR (chest symptomatic with sputum smear negative) were requested to assemble at the health facility on the designated date of visit of mobile unit. The health system staff ensured that the eligible patient made the visit. The chest x-ray interpretation was done by the District TB Officer who is a qualified chest physician or by the consultant of the Department of Respiratory Medicine at Medanta. Those with findings consistent with active TB (apical infiltrates, cavity, miliary nodules, pleural effusion—in corroboration with appropriate clinical findings) were diagnosed as smear negative pulmonary TB and were initiated on treatment as per RNTCP guidelines. The details of this strategy has been described elsewhere [9].
Strategy 2
The second strategy of enhanced case finding involved active information education communication (IEC) one week prior to the case finding activity. Pamphlets were distributed in the villages by the accredited social health activists (ASHAs). Banners were displayed in the health facility and radio/newspaper announcements were made to increase awareness amongst village residents both about the disease and about the visit of the mobile x-ray van. The RNTCP staff at district and Tuberculosis unit (TU) level, sarpanch and key local members was also involved in mobilizing the community. The mobile van visited 12 peripheral health institutes (PHIs) during Jan to March 2016. In this strategy, all chest symptomatic patients (cough > 2 weeks) underwent chest x-ray, regardless of their smear status. The reason for implementing Strategy 2 was the relatively low turnout of patients with Strategy 1. Strategy 2 followed new RNTCP guidelines 2016, which also recommend the use of chest x-ray where available, alongside sputum examination. A detailed proforma was filled for each patient recording all relevant details. Patients with abnormal x-ray findings were recalled for sputum smear microscopy. X-ray findings, sputum results, clinical presentation and previous TB status were taken into consideration by the doctor at the health facility before diagnosis of TB and starting treatment.
Data variables and source of data
Aggregate data (number of persons who underwent screening i.e. x-ray and/or sputum examination, number of persons with positive/negative x-ray finding and positive/negative smear result, number of persons started on DOTS) and cost estimates were collected from project records. Other variables such as socio-demographic (age, sex) and clinical characteristics (presence of symptoms such as cough, fever, weight loss, hemoptysis) and x-ray finding were also extracted from project records.
Cost analysis
Cost items were grouped into six categories: mobile van, x-ray equipment, personnel, operating costs (van insurance, annual maintenance costs and fuel), Information Education and Communication (for strategy 2 only) and miscellaneous. Cost estimates were obtained from project financial reports at 2016 prices. USD conversion rate of 2016 was used (1 USD = 64 INR).
Van and equipment
The one-time cost of van including fabrication (Rs 800,000) was estimated to be Rs 2,300,000 and for the equipment at Rs 620,000. The equipment consists of an Allenger’s 30 mA portable x-ray machine and a Fuji digital reader for digital review and printing of the x-ray. The mobile van and x-ray equipment were considered capital purchases, and only the annual depreciation was incorporated into the analysis. A depreciation time of 10 years was used for the analysis for the van and 7 years for the equipment. Operating costs included annual maintenance of the equipment, van insurance and fuel. The annual insurance for the mobile van was estimated at Rs 25,000. The details of the cost of various components are given in Additional file 1: Appendix 1.
Personnel
A nurse, a radiographic technologist (RT) and a driver were employed at Rs 15,000 per month.
Cost-effectiveness analysis
Considering five working days a week and two additional off days a month, a total of 18 camps are expected each month. A total of 13 and 50 patients visited each camp under strategy 1&2 respectively during the study period (first quarter of 2016). For strategy 1, total cost was divided by 2808 (13 patients per camp*18 camps/month*12 months) and for strategy 2, total cost was divided by 10,800 (50 patients per camp*18 camps/month*12 months) to get the cost per screening. In strategy 2, only 67 had their sputum tested among 108 with x-ray suggestive of TB (after excluding those already on treatment). All of them were started on TB treatment (11 smear positive and 56 smear negative). Sensitivity analysis was also performed examining cost estimates at different efficiencies of the mobile van in terms of the number of patients visiting each camp.
Analysis and statistics
Data were entered into Microsoft Excel and then imported into EpiData analysis V2.2.2.182 for analysis. We employed a trained radiographer cum data entry operators for this purpose. Data entry was also done daily after every camp as he was part of the screening team which accompanied the van. Data entry was regularly checked by the team leader, the nurse.
Proportions were used to summarize the aggregate data and the socio-demographic and clinical characteristics of those who were screened. A trend line was used to compare the case notification rate before and after the intervention in the study district.
Ethics approval
Ethical approval was obtained from the Institute Review Board of The Medanta - The Medicity Hospital, Gurugram, Haryana. Administrative approval to conduct the study was obtained from the State RNTCP, Haryana.