'Flogging a Dead Horse' Use of Socio Economic Status Scales in Health Research in India
The use of socio economic scales in health research in India has been at least five decade old practice now. There are a number of scales, which have been recommended for different population settings Kuppuswamy's scale for urban, Parikh's scale for rural, BG Prasad's scale for both rural and urban populations are amongst the most well known. In addition, scales such as Standard of Living Index (SLI) has been used by National Family Health Survey (NFHS) and the Deprivation Index has been used for SocioEconomic and Caste Census (SECC) in India. Each of these scales has the advantages and limitations, and for some, detailed analysis has been done and published in the past [1] A commonly used scale in academic research in medical colleges in India is Kuppuswamy's scale. This scale uses education and occupation of head of the family and the family income as three domains to assign socio economic status (SES) of a family. Nearly 2 decades ago, a modification to replace family incomewith per capita incomewas proposed in this scale and the proposed revision was referred as Modified Kuppuswamy's scale [2] Till now, there is no consensus on use of the original or the modified scales, and researchers go by their convenience in the selection of scale for the use. A few years later, an attempt was made to update the income criteria for Kuppuswamy's scale [3] which has, subsequently and almost ritualistically, been followed by different researchers and academicians to update the income based upon Consumer Price Index for Industrial Workers (CPI IW) and published in the peer reviewed journals. This issue of the journal carries an update on Kuppuswamy's scale suggesting a revision in two of the three domains of the scale occupation and income criteria [4] Kuppuswamy's scale is one of the most commonly used SES scale in academic research in India; in spite of this, there has not been much research evidence on the validity, utility, relevance, etc. of Kuppuswamy's scale. A recent study to validate the Kuppuswamy's and a few other SES scales used in India reported that by the use of these scales, a majority of the study families were being classified as upper socio economic strata [5] The comparative analysis with this scale and the wealth quintiles, deprivation criteria and poverty line etc. which are other pragmatic tools to provide an opportunity to direct limited resources (including health resources) to the people most in the need has also not been conducted. The practical utility of these scales appears limited and the basic information to do equity analysis (through wealth quintiles) apparently is not possible through these scales. Thus, it is not a surprise that in the last few years, a few critiques of the scales, highlighting the limitations have been published [1] It is also a bit intriguing that no serious attempt has been done in India to find or develop an alternative scale, except for one from researchers in Delhi, which apparently received limited response from academic community and has not been used by researchers since then [6] The lack of clarity on the practical application of this (and other related) scale and a suggestion for a revision in 2 of 3 domains of the scale as published in this issue of journal [3] amongst other, could be a sign that these SES scales have outlived their utility. It is likely that Indian researchers have been using these scales, more as a convention, for academic research while they themselves do not believe in the utility of these scales. In this background, it might be the timewhen the Indian research community should do away with the SES scales used till now or Chandrakant Lahariya c.lahariya@gmail.com
The Indian Journal of Pediatrics