Evaluation of latent tuberculosis infection surveillance in Peel region, Ontario, 2010–2014

Background: In Canada, identification and treatment of individuals with latent tuberculosis infection (LTBI) is a key component in preventing the progression of LTBI to active tuberculosis (TB). In Peel region, a large municipality in Ontario where half of the population is foreign-born, LTBI surveillance data are also critical to understanding the local epidemiology of TB. Objective: To evaluate LTBI surveillance data collected through the integrated Public Health Information System (iPHIS) from 2010 to 2014 by assessing data quality and usefulness and to provide recommendations to improve surveillance for Peel region. Methods: Using the European Centre for Disease Prevention and Control framework for surveillance evaluation, data quality was assessed based on completeness and validity of key variables in the iPHIS database. Usefulness of surveillance data in informing program decisions was assessed through interviews with stakeholders from Peel Public Health. Results: Of 6,576 iPHIS records evaluated, data for gender and date of birth were greater than 99% complete, while more than half of the risk factor fields were blank or 'unknown'. A comparison of 192 paper charts to the corresponding iPHIS record identified coding errors in over 40% of iPHIS risk factor fields. Treatment completion documented in iPHIS (20%) was lower than data obtained from a follow-up telephone survey of cases (50%). Stakeholders found surveillance data to be useful (100%), however, recommendations were made for improvement of data collection and analysis. Conclusion: Evaluating LTBI surveillance to improve data quality and usefulness for program planning is essential in an era of TB elimination. This evaluation resulted in standardization of data entry processes and continuation of direct follow-up with LTBI clients to confirm treatment completion. Work to understand barriers to treatment initiation and completion is currently underway.