Related Experiment Videos

Validation of a case definition to define hypertension using administrative data

Hude Quan1, Nadia Khan, Brenda R Hemmelgarn

  • 1Department of Community Health Sciences, University of Calgary, 3330 Hospital Dr NW, Calgary, Alberta T2N 4N1, Canada. hquan@ucalgary.ca

Hypertension (Dallas, Tex. : 1979)
|October 28, 2009
PubMed

Insights

Administrative data accurately identifies hypertension cases using a definition of "2 claims within 2 years or 1 hospitalization." This method is reliable for public health surveillance and research, showing high validity across different regions and time periods.

Area of Science:

  • Health Informatics
  • Epidemiology
  • Public Health Surveillance

Background:

  • Accurate case definitions are crucial for hypertension surveillance and research.
  • Administrative data offers a potentially vast and cost-effective data source.
  • Validation of administrative data definitions against physician charts is necessary.

Purpose of the Study:

  • To validate the accuracy of hypertension case definitions derived from administrative data.
  • To compare the validity of different case definitions across time and geographic regions.
  • To assess the utility of administrative data for hypertension case identification.

Main Methods:

  • Physician charts were randomly selected from urban and rural family physician clinics in Alberta and British Columbia, Canada (2001-2004).
  • Charts were linked to administrative data using unique personal health numbers.
  • Validity indices (sensitivity, specificity, PPV, NPV, kappa) were calculated for 8 case definitions using physician diagnoses as the gold standard.

Main Results:

  • The prevalence of hypertension ranged from 18.8% to 33.3% based on the year and region.
  • The definition '2 claims within 2 years or 1 hospitalization' demonstrated the highest validity (sensitivity 75%, specificity 94%, PPV 81%, NPV 92%, kappa 0.71).
  • Sensitivities were consistent across regions, years, and provinces after adjustments, though positive predictive value showed slight regional variation.

Conclusions:

  • Administrative data, particularly the '2 claims within 2 years or 1 hospitalization' definition, is a relatively valid source for identifying hypertension cases.
  • This validated definition supports the use of administrative data for large-scale hypertension surveillance and research.
  • Findings suggest administrative data can reliably define hypertension cases for public health initiatives.

Related Concept Videos

Hypertension I: Introduction01:28

Hypertension I: Introduction

Hypertension is a widespread, long-term medical condition where blood pressure in the arteries remains elevated. It is characterized by systolic blood pressure readings of 130 mm Hg or above or diastolic blood pressure (DBP) readings of 80 mm Hg or higher. Unmanaged hypertension poses significant health risks, making the distinction between primary (or essential) hypertension and secondary hypertension crucial, as their management and implications vary.Primary HypertensionPrimary hypertension,...
Hypertension III: Clinical Manifestations and Diagnostic Studies01:30

Hypertension III: Clinical Manifestations and Diagnostic Studies

Hypertension is asymptomatic and also referred to as the "silent killer" until it progresses to a severe stage or causes target organ disease. Patients may experience symptoms stemming from the strain on blood vessels and tissues in various organs or the heart's increased workload.Physical exams might show no abnormalities other than high blood pressure. Signs of vascular damage, when present, correspond to the organs supplied by the affected vessels, leading to target organ damage. For...
Hypertension V: Nursing Management01:23

Hypertension V: Nursing Management

The nursing management of hypertension involves accurately assessing symptoms, making a comprehensive nursing diagnosis, collaborating with patients to set goals, and implementing targeted interventions to mitigate the condition's impact and improve patient well-being.Comprehensive AssessmentThe initial step in nursing care for hypertension involves a thorough patient assessment. It includes evaluating symptoms such as headaches, dizziness, blurred vision, and previous hypertension episodes.
Errors occurring during blood pressure monitoring01:25

Errors occurring during blood pressure monitoring

Blood pressure monitoring is a crucial clinical procedure in diagnosing and managing various cardiovascular conditions. Despite its significance, the accuracy of blood pressure measurements can be compromised by multiple factors, potentially leading to either falsely high or low readings. These inaccuracies are critical as they can significantly impact patient care. So, it is vital to understand these challenges deeply and adopt strategic approaches to minimize errors.
Several factors...
Hypertension and Regulation of Blood Pressure01:18

Hypertension and Regulation of Blood Pressure

Hypertension, the most common cardiovascular disease, is diagnosed through repeated measurements of elevated blood pressure. Its risks, including damage to the kidney, heart, and brain, are directly proportional to blood pressure levels. Starting from 115/75 mm Hg, the risk of cardiovascular disease doubles with each increment of 20/10 mm Hg. The diagnosis relies on blood pressure measurements, not on patient symptoms, as hypertension is often asymptomatic until end-organ damage is imminent or...
Special considerations while measuring blood pressure01:28

Special considerations while measuring blood pressure

When assessing blood pressure (BP), healthcare professionals must consider various factors and potential unexpected outcomes to ensure accurate readings and provide proper patient care. Adhering to these guidelines is essential to achieving the most reliable results.
Monitoring Both Arms:
Monitoring BP in both arms during the initial assessment is advisable, as the systolic value may differ by five to ten mm Hg between arms. For subsequent BP assessments, use the arm with the higher reading.