Comparison of Two Survey Methods Based on Response Distribution of Pediatricians Regarding Immunization for Children in India: Mail versus Telephone

Abstract

Introduction: The use of telephone and mail surveys raises the question to what extent the results of different data collection methods deviate from one another. Aim: To determine if there is any difference in the response distribution between telephone and mail surveys of vaccination related-attitudes. Methods: A random sample of 400 pediatricians who are members of the India Academy of Pediatrics and work at various locations in India was selected. Mantel-Haenszel chi-square test was applied; significance level was alpha=0.05. Difference in percentage points of the majority response was calculated in the following way ∆=telephone% - mail%. Results: Only 36% responded to mail surveys and 57% responded to telephone surveys. Pediatricians in both telephone and mail surveys agreed for the majority of survey questions but to a different degree on particular items. More pediatricians in the telephone arm responded that measles eradication is important with a p=0.001 and ∆=8.3. More mail than telephone respondents reported that it is parents’ responsibility to ensure child is vaccinated (∆= -7.9, P=0.002) and that they would refer parents to a facility of their choice to get vaccines (∆=14, P=0.008). Conclusion: The results show evidence of the interviewer and/or social desirability bias and its influence on response choices. This suggests that mode of administration should be standardized or carefully adjusted for during analysis. Alternatively, further question development may minimize the sensitivity of items to mode of data collection.