Investigation to Identify the Cause of an Observed Change in Mortality Risk Attributable to Ozone

NOTICE OF PROPOSED PROCUREMENT (NPP)

Solicitation #: 1000173351 Closing Date: July 16, 2015 Time: 2 p.m. EDT

This requirement is for the department of Health Canada.

Title: Investigation to Identify the Cause of an Observed Change in Mortality Risk Attributable to Ozone

Scope: Considerable research over the last 20 years has established a clear and significant link between ground ozone levels and adverse health effects, including asthma, heart attack, strokes, and death. Early research, largely consisting of cohort studies using case-crossover designs, linked these health effects to long-term exposure to ambient ozone. Continued efforts led to evidence of links between short-term exposure to ozone and several health markers, including myocardial infarction and ischemic stroke, cardiovascular and respiratory diseases, and mortality. Several meta-analyses have contributed to the evidence in support of a scientific link between ozone exposure and mortality, with additional work finding that there is no safe threshold level for individual exposure.

The first substantive results linking ozone to human health dealt largely with long-term exposures. This was due to two reasons: lack of suitable data, and lack of suitable analytical frameworks (including computational power). The invention and popularization of Generalized Additive Models (GAMs), and the development of computing resources sufficient to estimate them, provided sufficient structure to allow for the estimation of health risk due to acute exposure. Prior to 2003, most scientific work linking ozone and health effects dealt with long-term ambient exposure, rather than short-term acute effects.

Since 2000, there has been a tremendous amount of work published on the relationship between acute exposure to air pollution (AP) and a variety of health outcomes. These outcomes include mortality, ischemic stroke and any number of other diseases. The majority of these studies use time-series regression models, typically computed in the framework of Generalized Additive Model (GAM) or Generalized Linear Model (GLM). Additionally, most such studies use one contiguous time block for analysis, e.g., 1987—2000 (the NMMAPS database), or 2000—2005 (analysis of the heat wave of 2003). An exception to this rule has been the Air Health Indicator (AHI) project, which seeks to model time trends in the risk.

The AHI project has developed models for estimation of risk due to acute exposure to air pollutants, primarily ozone and PM2.5 in Canadian urban centers. The principal investigator of the present proposal has developed multi-year risk estimators and proposed a 7-year estimator for the AHI using a simulation study based on Canadian data. There was further shown to be no evidence for either an increasing or decreasing trend in NO2 adverse health effects on Canadian population using single-year estimators. Using the 7-year estimator, however, the AHI has recently detected a substantial decline in ozone’s impact on Canadian heart or lung (cardio-pulmonary, CP) related mortality risks for the warm season from April to September. The decline seems to be strongly related to season and cause of mortality, as no change was observed in the cold season risk or in mortality from other causes. Further studies on historical ozone concentrations, the CP mortalities, additional confounders (e.g., heart or lung related drug usage), and correlations between ozone and ozone precursors (NOx, VOCs), and meteorological variables (MET, temperature, humidity, sunlight) are therefore necessary to prove or disprove the apparent declining trend in ozone-CP mortality associations at regional and national levels for warm season.

Objectives of the Requirement The objective of this project is to validate a signal from the AHI that indicates the relative risk of warm-season cardio-respiratory mortality per unit concentration of ground-level ozone has substantially shifted in recent years. If verified, to explore possible explanations for this change. This work is supposed to provide information on the following questions:

(1) How to best manage missing ground ozone concentration data? (2) How to best link drug usage to the ozone’s adverse health effects? (3) How to best link demo-socio-econimic data to the ozone’s adverse health effects? (4) How to best model synthetically lagged ozone risk estimates at regional and national levels minimizing bias in risk estimates? (5) How to best model warm season health risk using (1)-(4)?

Estimated Value: The total amount of funds available for this contract is $55,000, plus applicable taxes. A seven-month contract will be awarded to the bidder who receives the highest technical score on their technical proposal and who can do the work within the proposed budget.

Ownership of Intellectual Property: The Contractor will own the Intellectual Property, while the Crown will have an irrevocable, royalty-free licence to use the IP.

Security Requirement: There is no security requirement.

Mandatory Requirements

M1. The bidder’s project leader must have a PhD from a recognized university with specialization in Statistics with experiences in public health, environment or epidemiologic studies.

M2. The bidder’s project leader must demonstrate that within the last 5 years, he/she has undertaken at least one project on Canadian health or clinical trials.

M3. The bidder’s project leader must have at least one peer-reviewed publication on statistical method development in scientific journals listed in the Science Citation Index Expanded (within the last 5 years).

M4. The bidder’s project leader must show that they have experience working with Canadian databases on drug, demographic and/or socio-economic status.

M5. The bidder’s project leader must have experience working with generalized additive models, generalized Poisson models and/or hierarchical models.

M6. The bidder’s project leader must show that they have experience working with statistical software such as R.

Selection Methodology The contract will be awarded to the bidder with the highest technical score who can commit to perform the work described in the Statement of Work for an amount not to exceed $55,000, taxes not included.

Enquiries regarding this Request for Proposals are to be submitted in writing to

Robert Merrick Contracting Authority E-mail: Robert.Merrick@hc-sc.gc.ca