QM Test 1

What is a control chart?

modified trend chart in which upper and lower control limits are placed with a central line that indicates an accepted norm. Points above or below these control limits indicate unstable process. Invented by Walter Shewhart at Bell Labs in 1920 so can be called Shewhart Chart or process/behavior chart. Cannot identify a specific cause but rather if and when they occurred like the trend chart.

What is a Pareto Chart?

named after Wilfred Pareto an Italian political economist. Is a variation of the histogram bar graph in which prioritizes the most frequent problems at the y-axis and the other problems in decreasing order to the right. Pareto Chart was developed to illustrate 80/20 Rule. Useful in identifying main causes of problems and in demonstrating the results of improvements that have been implemented. They document frequency of causes and not the severity of the cause!

NCRP advises against these doses for pregnancy:

.025 msV per day .5 msV per 1 month 5 msV entire pregnancy

Thicknesses for shielding?

.25 mm Aprons .25-.5 Gloves .5 at least for thyroid .35-.5 eyeglasses

Visitor doses:

1 msV and 5 msV per year depending on how often and age

What are the 3 types of validity in survey measurement?

1. Construct: is the extent to which a measure would agree with other survey instruments that have been made to measure the same parameters and have proven accuracy. 2. Content: extent to which a survey will cover all of the content area. 3. Criterion: compares the results obtained in a survey to an established criterion measure

What are certain administrative procedures TQM requires of all radiologists, administrators, QC technologists, quality improvement committees, and imaging professionals?

1. Establish thresholds of acceptability- levels of accuracy, specificity, and sensitivity to diagnosis. Established by both external (federal/state guidelines or professional/accrediting agencies) and internal factors which are based on the needs and resources of the individual department 2. Establish an effective communication network-communication essential for successful QM program. Need to be able to work with other departments to effectively improve patient quality of care. Administrators make sure all personnel are competent with computers and know HIPPA requirements. 3. Provide for patient comfort- convenience and privacy is a must. Want good patient satisfaction surveys. 4. Ensure accepted performance of imaging professionals- documentation and review 5. Develop a record-keeping system- to document QM and QC procedures that are being implemented and are in compliance with accepted norms. 6. Establish corrective actions- failures must be documented. Inservice education or other corrective action procedures may be needed. Flow charts are useful.

When discussing quality of patient care and the diagnostic images we produce we must keep in mind the 3 levels on which quality is determined. What are they?

1. Expected Quality- This is the level of quality of the product/service that is expected by the customer and may be influenced by outside factors such as prior word of mouth from friends/family. A diagnostic imaging professional would likely have the least amount of impact on this level because it is present before the patient comes into the imaging department. 2. Perceived Quality- This is the customer's perception of the product/service. It is based on the customer's perception of the product/service and is highly subjective and difficult to measure quantitatively. For patients undergoing exams their experience during the procedures greatly influence their perception of quality. Therefore, how well an imaging professional performs their job will have the greatest impact on this level of quality. Because perceived quality is often what brings patients back to a hospital or imaging center it can be more important than the actual quality. 3. Actual Quality- This level of quality uses statistical data to measure outcomes and considers all factors that can influence the final outcome. It also can compare the quality of the product/service with that of a competitor.

What are the key concepts of an effective risk management program?

1. Risk Analysis 2. Written policies and procedures 3. Employee Education 4. Periodic Inspection 5. Record Keeping

What are 3 things that can impact reliability in obtaining statistical information?

1. Sample Size (larger the better) 2. Design of Data Collection Process (are the survey questions worded in a "biased" way) 3. Collection and Interpretation of Data (is the person that is collecting the data including all information that is given?)

What are the 2 types of variation?

1. Special Cause: assignable to a specific cause and arises because of special circumstances 2. Common Cause: due to the process/system itself and the people involved.

What are the 2 categories of measurement errors?

1. Systematic/Determinate Errors- result from factors such as malfunctioning equipment, not correcting outside influences, and poor design in data collection process. 2. Random/Indeterminate Errors- result from statistical fluctuations/uncertainties such as quantum mottle.

Gloves and aprons are a must if dose is?

5 mR/hr or more

What is the avg effective dose of background radiation?

360 mrem or 3.6 msV

What is the avg effective dose of diagnostic radiographs?

39 mrem or .39 msV

NCRP report 116 says max effective dose for occupational personnel regarding whole body, eyes, and other body parts include:

50 msV, 150 msV, 500 msV per year

What is a histogram?

A data display tool in the form of a bar graph that often plots the most frequent occurrence of a quantity in the center. Area of the bars is what denotes the value not the height as in bar graphs Continuous data often best displayed with a histogram. Also can help demonstrate the amount of variation in a particular process. (monthly repeat rate, number of exams each month, etc.) Scorecard display in computers color coordinates and allows benchmarks to be determined.

What is the ability to measure what is purported to be measured? Known as validity. How well a value that has been measured/studied reflects the true value.

Accuracy

A systematic or nonrandom difference between the true value of a property and individual measurements of that property or the presence of a systematic error. Often inaccurately thought of as prejudice.

Bias

How are the 4 components of comprehensive QM programs implemented?

By the collection and analysis of data through the use of statistics.

In Poisson Statistics, how is the standard deviation determined?

By the square root of the mean

What is a cause-and-effect diagram?

Casual analysis tool also known as a fishbone chart or Ishikawa diagram. Developed by Kaoru Ishikawa of the University of Tokyo in 1943. Used to demonstrate graphically the causes and effects of different variables or conditions on a key quality characteristic, thereby, potential areas of improvement. Most useful in identifying multiple causes of problems during root cause analysis studies. To construct you must first determine the key quality characteristics to be improved. Then potential causes of the effect must be identified. Brainstorming by a quality improvement team or similar group may be helpful with this. Main ideas listed on branches flowing toward the main branch and grouped according to categories. All possible problems or causes for each of these main ideas must then be listed as subcauses within each branch.

What is referred to as the central position of a sample frequency and is commonly measured by mean, median, and mode?

Central Tendency

What are the 3 classifications of all medical devices the FDA uses?

Class 1: general controls Class 2: special controls Class 3: premarket approval

What kind of variables have an infinite range of mathematical values? i.e. Age, Weight, Height of patients, or time of an event.

Continuous Variables

What are variables in statistical studies that change in response to independent variables? i.e. Not controlled in the study. Also known as response, measured, and output variables.

Dependent Variables

What kind of variables are studied with only 2 opposing choices? i.e. Male/Female and On/Off.

Dichotomous Variables

What is measurement error?

Difference between the measured and true value of the variable being measured.

Caution sign if?

Dosage can exceed 5 mR/hr

Comprehensive QM programs for imaging departments, regardless of size, should contain at least what four components?

Equipment QC, Administrative Responsibilities, Risk Management, and Radiation Safety Programs.

Who regulates the design and manufacture of x-ray equipment and whose regulations are contained in the document Title 21 of the Code of Federal Regulations Part 1020?

FDA through the Center for Devices and Radiological Health

What 7 basic statistical tools are used to display data for interpretation and analysis?

Flowcharts, Cause-and-Effect Diagrams, Histograms, Pareto Charts, Scatter Plots, Trend Charts, and Control Charts

What is the term for a number of times a particular value/variable occurs or the number of observations of an event?

Frequency

What type of distribution is the basis of Six Sigma where 99 percent of all variables are covered?

Gaussian Distribution

What is known as normal distribution and represents a curve that is bell shaped and continuous with both tails extending to infinity?

Gaussian Distribution created by German mathematician Fredrick Gauss

As the mean increases, the variance does what?

Increases

What variables are deliberately manipulated to invoke change to dependent variables? Also known as predictor and input variables.

Independent Variables

What is statistics and why is it important to the comprehensive QM components?

Mathematical science pertaining to collection, analysis, and interpretation/presentation of data. This data then can be used to verify success of processes or provide justification for changing/improving processes.

What measurement of central tendency is calculated by the avg set of observations (sum of observed values/total # of values) and provides greatest reliability of the 3?

Mean

What measurement of central tendency is exactly 1/2 of above and below values. (Numerical Middle)

Median

What measurement of central tendency is the value occurring with the greatest frequency of a data set? Provides information for most typical occurrence and is referred to as a rough estimate for the central value.

Mode

Which agency is responsible for enforcing both equipment standards and radiation safety practices and whose regulations are contained in Title 10 of the Code of Federal Regulations Part 20?

NRC which refers to department of energy. They allow agreement states to make their own equipment and radiation safety standards.

What is a sample and why are they useful tool in information analysis?

Number of items actually measured from a population. Must be chosen wisely to accurately represent the population. Populations can be large/difficult to study so a sampling involves choosing a portion/subset of the population to make data collection more practical, timely, and efficient.

What is the purpose of quality management?

Numerous sources of variability, in both human and equipment factors can produce sub quality images if not properly controlled. This can result in repeat exposures that increase both patient dose and department cost. This in turn can result in decreased customer satisfaction (physicians, vendors, insurance companies, employees, and patients) that ultimately costs the healthcare provider lost business and revenue. In diagnostic imaging department these variables include equipment; image receptor; processing; viewing conditions; and competency of the technologist, support staff, and the observer/interpreter.

Which agency is responsible for establishing standards for safety and monitoring the work environment, including occupational exposure, handling/disposal of hazardous material, universal precautions (transmission and protection) and is found in Title 29 of the Code of Federal Regulations part 1910?

OSHA

What is a Flowchart?

Pictorial representation of the individual steps that can be contained in a process. Designed to present sequence of events in a process from beginning to end. Can demonstrate problem areas, inconsistencies, redundancies, that can produce variations in the output process which may result in system failure. May also be used to document current processes, redesign current processes, and design new ones. Easy to construct but typically best developed by persons who are directly involved in or have knowledge of the particular process presented. Before design, one must identify all of the inputs, outputs, and actions within the process, as well as the sequence in which they occur. Then symbol can be chosen for each step in the process. Allows for easy communication of the process and outcomes to staff. Also allows a project improvement team to examine the process in order to be able to improve it.

Discrete probability distribution to determine whether events occur randomly or not. The variance is equal to the mean and is generally asymmetrical for low means (<10) which is opposite of Gaussian.

Poisson Distribution created by French mathematician Simeon Poisson

What is the term for an entire set/group of items being measured and identification of this is one of the 1st steps of statistical analysis?

Population

What is TQM devoted to?

Process improvement so that goods and services can be delivered more efficiently to increase customer satisfaction.

What is the difference of the highest and lowest data values and is a measure of the dispersion of data distribution?

Range

What is variation?

Range of output around the central measure of a process.

NCRP Report 107 refers to what?

Recommendations for the ALARA program

What is the consistency of repeated measurements of the same thing or the reproducibility of a result and is also known as precision?

Reliability

Range of variation/dispersion of a set of values surrounding the mean or the spread of distribution of a data set. Can be applied to random variables, populations, probability distributions, and/or multisets. Defined as root mean square deviation of the values from their mean.

Standard Deviation

How are the measurements in Gaussian Distribution characterized?

Symmetric about the mean value of the measurement set with spread of the measurements characterized by their standard deviations. 68 percent of all values fall within 1 SD on either side of the mean, 95 percent within 2 SD, and 99 percent within 3 SD.

What is a data set?

The information/measurements acquired by evaluating the particular sample.

What are some things that may result in large standard deviations?

The way measurements were obtained, measured, or calculated. Important to remember large variations could be a normal occurrence for a particular data set making it valid.

Why do we use standard deviation?

To measure statistical dispersion. How far values in a data set are from their mean. Closer the points are to their mean, the smaller the deviation. Validity of SD value MUST be determined before results of a study can be considered valid.

Square of the standard deviation in Poisson Statistics and is used to determine if separate means of several different groups differ significantly from one another. (male/females, age groups). Also used for dispersion/spread of a set of values.

Variance

NCRP Report 116 refers to what?

Visitor and Personnel protection

What is the "start up effect" and how should it be avoided?

When new QM programs have unreliable data at first. Human tendency is hyperaware in the start of new studies so data results are unusually high/low. Give enough time for data to change/stabilize before trying to obtain reliable data.

What is statistical inference in regards to sampling?

When only certain people are actually monitored/evaluated and the results are extrapolated to represent the entire population.

What is a trend chart?

also known as a run/run-sequence chart. Pictorially demonstrates whether key indicators are moving up or down over a given period of time, on an ongoing basis. Trending refers to the evaluation of data collected over a given period of time for the purpose of identifying patterns/changes.

What are scatter plots?

traditional 2 axis graph with several data points that have been plotted. Designed to determine whether a relationship exists between 2 different variables in a process. Scatter patterns determine correlations between 2 variables. Positive= when they both increase. Negative= when x increases and y decreases.