Achieving Data Quality in a Statistical Agency: A Methodological Perspective DATA DETECTIVES: UNCOVERING SYSTEMATIC ERRORS IN ADMINISTRATIVE DATABASES

Secondary users of health information often assume that administrative data provides a relatively sound basis when making important planning and policy decisions. If errors are evenly and/or randomly distributed this may have little impact. This assumption is betrayed when information sources contain systematic errors, or when systematic errors are introduced in the creation of master files. The most common systematic errors involve underreporting of activity for a specific population, inaccurate re-coding of spatial information, or differences in data entry protocols. The Central East Health Information Partnership (CEHIP) provides information support for development of public health programs and health system planning through a partnership in Ontario’s most populous health planning region. CEHIP has identified a number of systematic errors in administrative databases and has documented many of these in reports distributed to partner organizations. Failures to register births and incorrect assignment of geographic codes in vital statistics files have been studied. Misclassification of cause of death has also been explored, particularly with respect to delays in determining cause of death and the effect this has on official data sets. Differences in data entry protocols for reportable disease data have been researched, raising questions about the consistency of data submitted by different tracking agencies. This paper will describe how some of these errors were identified, and note processes that give rise to such losses in data integrity. The conclusion will address some of the impacts these problems have for health planners, program managers and policy makers

Brain responses to semantic incongruity in bilinguals

Event-related potentials were examined in the first and second languages of bilinguals, and in monolinguals. Stimuli were anomalous sentences presented one word at a time on a CRT monitor. The principal dependent measure was the N400 component, and an accompanying frontal negativity, which provided an estimate of the amount of time the nervous system takes to determine the semantic incongruity of a given word. The results indicate that N400 latency is slightly, but significantly, delayed in bilinguals, with monolinguals having the shortest mean N400 latency, the first language of bilinguals next, and the second language of bilinguals longest. The frontal negativity varied in amplitude somewhat independently of the parietal N400. The amplitude of the frontal negativity was sometimes reduced in the second language, tending to be smaller in those subjects who used their second language the least. Neither N400 nor the frontal negativity varied as a function of age of acquisition of the second language. The results are discussed with reference to the relative automaticity of language in bilinguals, and the sensitivity of N400 to variations in the automaticity of language processing.</p

Making health system performance measurement useful to policy makers: aligning strategies, measurement and local health system accountability in ontario

This study examined the experience of the Ontario Ministry of Health and Long-Term Care in enhancing its stewardship and performance management role by developing a health system strategy map and a strategy-based scorecard through a process of policy reviews and expert consultations, and linking them to accountability agreements. An evaluation of the implementation and of the effects of the policy intervention has been carried out through direct policy observation over three years, document analysis, interviews with decision-makers and systematic discussion of findings with other authors and external reviewers. Cascading strategies at health and local health system levels were identified, and a core set of health system and local health system performance indicators was selected and incorporated into accountability agreements with the Local Health Integration Networks. despite the persistence of such challenges as measurement limitations and lack of systematic linkage to decision-making processes, these activities helped to strengthen substantially the ministry's performance management functio

Modelling strategies for controlling SARS outbreaks

Severe acute respiratory syndrome (SARS), a new, highly contagious, viral disease, emerged in China late in 2002 and quickly spread to 32 countries and regions causing in excess of 774 deaths and 8098 infections worldwide. In the absence of a rapid diagnostic test, therapy or vaccine, isolation of individuals diagnosed with SARS and quarantine of individuals feared exposed to SARS virus were used to control the spread of infection. We examine mathematically the impact of isolation and quarantine on the control of SARS during the outbreaks in Toronto, Hong Kong, Singapore and Beijing using a deterministic model that closely mimics the data for cumulative infected cases and SARS-related deaths in the first three regions but not in Beijing until mid-April, when China started to report data more accurately. The results reveal that achieving a reduction in the contact rate between susceptible and diseased individuals by isolating the latter is a critically important strategy that can control SARS outbreaks with or without quarantine. An optimal isolation programme entails timely implementation under stringent hygienic precautions defined by a critical threshold value. Values below this threshold lead to control, but those above are associated with the incidence of new community outbreaks or nosocomial infections, a known cause for the spread of SARS in each region. Allocation of resources to implement optimal isolation is more effective than to implement sub-optimal isolation and quarantine together. A community-wide eradication of SARS is feasible if optimal isolation is combined with a highly effective screening programme at the points of entry

Modelling strategies for controlling SARS outbreaks

NRC publication: Ye