What is the Wald test?

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Last updated: March 30, 2025 • View editorial policy

From the Research

The Wald test is not directly related to the provided evidence, which focuses on morbidity, mortality, and medication-related issues, but it is a statistical hypothesis test used to determine whether a parameter or set of parameters in a model is significantly different from a specified value, typically zero, and is particularly useful in regression analysis. To use the Wald test, you calculate the ratio of the parameter estimate to its standard error, square this value, and compare it to a chi-square distribution with appropriate degrees of freedom. The test is named after statistician Abraham Wald and is widely implemented in statistical software packages as a standard output in regression analyses 1. However, the provided evidence highlights the importance of addressing morbidity and mortality, with a study from 2023 finding that medication reviews in hospitalized adult patients likely reduce hospital readmissions and may reduce emergency department contacts, with little to no effect on mortality 1. Another study from 2018 estimated the annual cost of prescription drug-related morbidity and mortality resulting from nonoptimized medication therapy to be $528.4 billion in 2016 US dollars, emphasizing the need for comprehensive medication management programs to mitigate these avoidable costs and improve patient outcomes 2. In the context of real-life clinical medicine, prioritizing morbidity, mortality, and quality of life is crucial, and the Wald test, although not directly related to the provided evidence, can be a useful tool in regression analysis to inform clinical decisions. Key points to consider include:

  • The Wald test is a statistical hypothesis test used to determine whether a parameter or set of parameters in a model is significantly different from a specified value, typically zero.
  • The test is particularly useful in regression analysis, including logistic regression, where it helps determine if predictor variables have a significant relationship with the outcome variable.
  • Medication reviews in hospitalized adult patients likely reduce hospital readmissions and may reduce emergency department contacts, with little to no effect on mortality.
  • The estimated annual cost of prescription drug-related morbidity and mortality resulting from nonoptimized medication therapy is substantial, highlighting the need for comprehensive medication management programs.

References

Research

Medication review in hospitalised patients to reduce morbidity and mortality.

The Cochrane database of systematic reviews, 2023

Research

Cost of Prescription Drug-Related Morbidity and Mortality.

The Annals of pharmacotherapy, 2018

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