Comparing Quality Improvement Graphical Tools

¶ … Quality Improvement Comparison of Graphical Tools used in Quality Improvement Quality Improvement Tool Comparison Matrix Quality Improvement Tool Uses Bar Graph (StatSoft, 2014a) Values for a single variable is represented by bars or columns Each bar represents a single case and the value of the variable (time, temperature, etc.…) is denoted by the Y-axis Histogram (StatSoft, 2014b) Graphical representation of a frequency distribution for a variable, with columns or bars representing the distribution of class intervals and the height of the columns representing the frequency of each class Control Chart (StatSoft, 2014c; Trusko, Pexton, Harrington, & Gupta, 2007, p.

146-149) Compares the means and ranges for a variable using two line charts, although vertical histograms can be incorporated into the chart as well to facilitate visualization of how much values are deviating from the expected norm Bar graphs are seemingly ubiquitous, in part because of the inherent simplicity of the data representation. Bar graphs can be used to represent the value of a variable for each case in a series (StatSoft, 2014a).

For example, a bar graph can be used to compare the performance values of healthcare quality standards nationally, regionally, and within a health system (U.S. Department of Health and Human Services, 2011). By comparison, a histogram provides a graphic representation of the values for a frequency distribution using bars or columns (StatSoft, 2014b). One example would be to chart the annual length of stay for all adult ICU inpatients at tertiary-care teaching hospitals nationally.

The bars would represent intervals of days or hours, while the height of the bars would represent the number of hospitals belonging to that time interval. While the histogram is a type of bar graph, the information it represents is therefore distinct from the information that is represented by a bar graph.

If the length of stay data were represented by a bar graph, each bar would represent a hospital, but if the hospitals were to be grouped by length of stay performance then that would be a histogram, if the height of the bars represented the number of hospitals belonging to each performance group. A quality control chart is a more specialized tool, when compared to bar graphs and histograms.

Its purpose is to track the performance of a process over time, thereby determining whether it is behaving normally or out of control (StatSoft, 2014C; Trusko et al., 2007, p. 146-149). Should a performance measure exit normal limits, remedial action would need to be taken to bring it back within normal limits. An important benchmark of quality for any hospital or long-term care facility is the prevalence of hospital-acquired pressure ulcers (HAPU). A hospital in Ohio discovered that the prevalence of HAPU was 11.8% within 849 adult admissions (Corniello et al., 2014).

A large number of predictors were identified, of which several could be incorporated into a quality improvement project. The team leader(s) for the quality improvement project could set a HAPU prevalence rate goal of 3%, with an upper and lower control limit of 5 and 0%, respectively. If the outcome was examined using a quality control chart, the goal of 3%, along with the upper and lower control limits would be displayed.

The upper chart would represent the mean HAPU rate over time, while the lower chart might show the range of HAPUs per patient or length of stay. By comparison, bar graphs and histograms would not.