Module Components

• Overview
• Assignments

Topics

• Common Parametric and Nonparametric Procedures for Testing Changes over Time
• Quality Improvement: Measurment
• Quality Improvement: Variation
• Run Charts
• Statistical Process Control Charts

NRSG 795: BIOSTATISTICS FOR EVIDENCE-BASED PRACTICE

Module 11: Testing Differences Over Time

Quality Improvement: Measurement

Measurement is a critical part of testing and implementing changes; measures tell a team whether the changes they are making actually lead to improvement. It is a step in improving health care quality, and quality measures help drive that improvement through a consistent and accountable approach.

What is a Quality Measure?

Quality measures, which can also be referred to as Clinical Quality Measures (CQMs) and electronic Clinical Quality Measures (eCQMs), are tools that help measure or quantify healthcare processes, outcomes, patient perceptions, and organizational structure and/or systems that are associated with the ability to provide high-quality health care and/or that relate to one or more quality goals for health care. These goals include: effective, safe, efficient, patient-centered, equitable, and timely care.

Types of Measures

Outcome measures: Outcome measures reflect the impact of the health care service or intervention on the health status of patients.

• The percentage of patients who died as a result of surgery (surgical mortality rates).
• The rate of surgical complications or hospital-acquired infections.
• Average hemoglobin A1c level for population of patients with diabetes
• Adverse drug events per 1,000 doses

Structural measures: Structural measures give consumers a sense of a health care provider’s capacity, systems, and processes to provide high-quality care.

• Whether the health care organization uses electronic medical records or medication order entry systems.
• The number or proportion of board-certified physicians.
• The ratio of providers to patients.

Process measures: Process measures indicate what a provider does to maintain or improve health, either for healthy people or for those diagnosed with a health care condition. These measures typically reflect generally accepted recommendations for clinical practice. They can also inform consumers about medical care they may expect to receive for a given condition or disease, and can contribute toward improving health outcomes. The majority of health care quality measures used for public reporting are process measures.

• The percentage of people receiving preventive services (such as mammograms or immunizations).
• The percentage of people with diabetes who had their blood sugar tested and controlled.
• Average daily clinician hours available for appointments.

Balancing measures: Balancing measures determine whether changes designed to improve one part of the system are causing new problems in other parts of the system.

• You would need two different satisfaction scores to be able to investigate whether a new QI change to improves staff satisfaction decreased client satisfaction?
  

Components of a Measure

A measure is made up of several components.

1. A title and description of what it is.
2. The numerator, which is also called the measure focus, describes the target process, condition, event, or outcome expected for the targeted population.
3. The denominator defines the population being measured—it could be the whole population or a subset.
4. The denominator exclusion identifies members of this population who should be removed from the measure population, and hence the denominator, before determining if numerator criteria are met.

Example of a measure designed to promote the most effective prevention and treatment practices for patients with hypertension.

Measure Title: Controlling High Blood Pressure

Description: Percentage of patients 18-85 years of age who had a diagnosis of hypertension and whose blood pressure was adequately controlled (< 140/90 mmHg) during the Quality Improvement: Quality Improvement: Measurement period

Numerator: The number of patients in the denominator whose most recent BP is adequately controlled during the Quality Improvement: Quality Improvement: Measurement year. For a patient’s BP to be controlled, both the systolic and diastolic BP must be <140/90 (adequate control). To determine if a patient’s BP is adequately controlled, the representative BP must be identified.

Denominator: Patients 18 to 85 years of age by the end of the Quality Improvement: Quality Improvement: Measurement year who had at least one outpatient encounter with a diagnosis of hypertension (HTN) during the first six months of the Quality Improvement: Quality Improvement: Measurement year.

Denominator Exclusions: Exclude all patients with evidence of end-stage renal disease (ESRD) on or prior to the end of the Quality Improvement: Quality Improvement: Measurement year. Documentation in the medical record must include a related note indicating evidence of ESRD. Documentation of dialysis or renal transplant also meets the criteria for evidence of ESRD. Exclude all patients with a diagnosis of pregnancy during the Quality Improvement: Quality Improvement: Measurement year. Exclude all patients who had an admission to a nonacute inpatient setting during the Quality Improvement: Quality Improvement: Measurement year.

Choosing the appropriate type of measure to understand your system

Raw data is hard to compare so statistics are used to organize and summarize the information that is collected. The basic summarizing statistics used in quality improvement efforts are:

Counts: A count of how many items or observations
Example: the number of people responding to a survey

Sums: Adding up the number of items or observations
Example: 20 out of 100 people surveyed feel that communication with their healthcare provider is inadequate

Ratio: A fraction that describes two groups relative to one another.
Example: the ratio of females to males in the study

Rate: A ratio that describes one quantity in relation to a certain unit.
Example: the rate of infection expressed per 1000 patients

How you choose to present your data will depend on the nature of your data and how you plan to use it.  Rates, ratios and percentages help you standardize your data so that it is expressed in a meaningful way that can be readily compared with other data.

Percentages are used to indicate fractions and often indicate proportions. It is defined as the # events of interest / total population of interest [the numerator cannot be larger than he denominator). Percent is a rate per 100.

Rate is a ratio between two related quantities. It can be defined as the # events over a specified time period / population at risk for that event over time [numerator can be larger than the denominator]

Ratio is the relationship of two numbers. It may be used to adjust for the impact of natural changes in your system, such as volume. The numerator is the key measure (e.g., costs, patients waiting) and the denominator is the unit of production or volume (e.g., total costs, total patients waiting). For example, if the number of patients waiting for more than one hour increased dramatically, you might draw one conclusion. If you knew that overall volume had also increased (which would show up in the ratio), you would mostly likely draw another, more accurate, conclusion.

Sample measures: http://www.ihi.org/resources/Pages/Measures/default.aspx

Required Readings and Videos

Gupta M, Kaplan HC. Improving Quality Improvement in Neonatal-Perinatal Care. Clin Perinatol. 2017 Sep;44(3):xvii-xix. doi: 10.1016/j.clp.2017.06.002. pages 962-964.

This article also contains content relevant to subsequent sections of this module.

This video explains the seven steps to Quality Improvement: Quality Improvement: Measurement for improvement (9:25). https://www.youtube.com/watch?v=Za1o77jAnbw