Lecture 22: Research and Non-Systems

Steps for evidence-based practice

- Identify problem

- Pose a clinical question

- Find literature to answer that question

- Critically appraise the search article

- Find clinical relevance

- Clinical application of this new intervention

Two PT students are reviewing the literature for the effects of cupping technique to increase hamstrings flexibility. According to levels of evidence, which studies provide the BEST evidence for support of cupping in increasing the hamstrings flexibility?

A. Clinical case report

B. Randomized controlled trials

C. Clinical case series

D. Cross sectional studies

B. Randomized controlled trials

RCT is the strongest form of evidence. A study in which people are allocated at random (by chance alone) to received one of several clinical interventions. One of these interventions is the standard of comparison or control. The control may be a standard practice, a placebo (“sugar pill”), or no intervention at all.

Case series

- Also known as a clinical series

- Medical research study that tracks subjects with known exposure, such as patients who have received a similar treatment, or examines their medical records for exposure and outcome

Cross sectional studies

- Make comparisons at a single point in time

- Longitudinal studies make comparisons over time

Strongest level of evidence

Meta-analysis/ systemic review

Weakest level of evidence

Case reports

Levels of evidence from strongest to weakest

- Meta-analysis/systemic review

- Randomized controlled trials

- Cohort

- Case control

- Cross-sectional studies

- Case series

- Case reports

Meta-analysis

A procedure for statistically combining the results of many different research studies

Cohort study

A group of exposed individuals (individuals who have been exposed to the potential risk factor) and a group of non-exposed individuals are followed over time to determine the incidence of disease

Case control

A type of epidemiologic study where a group of individuals with the diseases, referred to as cases, are compared to individuals without the disease, referred to as controls

Case report study

Type of descriptive research in which only one individual is studied in depth

Three DPT students are looking at effects of drugs on falls. The students are using data from previous patient medical records to compare drug usage in fallers and non-fallers. Which of the following will be the MOST appropriate study design?

A. Clinical case report

B. Retrospective cohort

C. Randomized controlled trials

D. Prospective cohort

B. Retrospective cohort

Retrospective cohort

- Individuals are sampled and information is collected about their past

- Can be done on ANY already collected data

Types of research

- Qualitative

- Quantitative

Qualitative research

- Does not use statistical methods

- Patients emotions and feelings related to his problem

Qualitative research includes:

- Observation

- Interviews

- Questionnaires focusing on people's emotional approach to their problems

Quantitative research

- Uses statistical methods

- All variables are measured with outcome measures and data analysis done

Which of the following instruments is MOST appropriate for measuring patients' quality of life?

A. Dynamic Gait Index (DGI)

B. Oswestry low back pain disability index (ODI)

C. Timed up and go test (TUG)

D. Medical Outcomes Study 36-item short form (SF-36)

D. Medical Outcomes Study 36-item short form (SF-36)

Self-report that covers eight domains of physical functioning, role limitation due to physical problems, role limitations due to emotional problems, fatigue, and general health perceptions.

Levels of measurement: qualitative

- Nominal

- Ordinal

Nominal measurement

- Used in nonparametric data

- Basic level of differentiation in groups

- Example: Diff between males- females, blood type, types of breath sounds, types of arthritis

Ordinal measurement

- Used in nonparametric data

- Data measured in ranks

- Example: MMT grades, level of assistance, joint laxity grades

Level of measurement: quantitative

- Discrete = interval & ratio

- Continuous = interval & ratio

Interval measurement

- Used in parametric data

- This does not have true zero

- Example: temp in Celsius/Fahrenheit, developmental and functional status scales.

- Explanation of why Celsius is Interval- Zero degrees Celsius does not represent the complete absence of temperature..

Ratio measurement

- Highest level of measurement scale, used in parametric data

- This has a true zero.

- Example: ROM, Nerve conduction velocity, distance

walked.

Discrete measurement

- Range of specified numbers is complete

- Examples: number of planets around the sun; number of students in a class

Continuous measurement

- Range of specified numbers is incomplete i.e. infinite

- Examples: number of stars in the sky; height or weight of students in a class

A researcher is collecting ROM data on volleyball players during shoulder abduction motion. The results of the tests are BEST categorized as which of the following types of data?

A. Interval data

B. Ordinal data

C. Nominal data

D. Ratio data

D. Ratio data

With ratio data, you have a true zero. With ROM, if you have 0 deg, you legit have no ROM.

Absolute/true zero means that the zero point represents the absence of the property being measured.

Data collection techniques

- Surveys

- Direct observation

- Randomization

- Convenience samples

Intra-rater reliability

Test performed by 1 person several times

Inter-rater reliability

Test performed by 2 or more individuals on different subjects testing 1 variable

Test-retest reliability

- Same test to the same individuals on 2 occassions

- Problem of the equipment or the test itself

The PT will measure distance between spinous process to inferior angle at 0, 60 and 100 abduction at three different time points. One of the MOST important factors for the success of this study is:

A. Face validity

B. Intra-rater reliability

C. Inter-rater reliability

D. Content validity

B. Intra-rater reliability

Content validity

- Test should measure specifically what the patient problem is

- E.g.: For testing balance, BERG balance can be done

Construct validity

- Test should measure what its supposed to measure

- E.g.- Goniometer should measure ROM nothing else

Concurrent validity

- Test performed and compared to the gold standard test and results are matched

- Heart rate measured by peripheral pulses and compared with ECG readings

Face validity

- The outcome measure should measure what is looks like it will measure related to patient problem

- When an assessment or test appears to do what it claims to do

- Survey to measure the regularity of dietary habits

Two PTs perform a test on a patient using the Berg balance scale. The patient visit is Monday (M) and Wednesday (W). One PT reports scores of 29 and 30 on M & W; other PT scored 36 and 37 (M&W). This is indicative of a problem in:

A. Concurrent validity

B. Intraraterreliability

C. Interrater reliability

D. Construct validity

C. Interrater reliability

A PT receives a referral for a patient who is one week status post CVA. When observing the patient lying in bed, PT notes that the patient's calf and foot are edematous. The patient reports that the area is somewhat painful. The PT should:

A. Discontinue the examination and wait till the swelling on the patient's leg decreases

B. Order compression stockings for the patient to relieve the edema

C. Continue with the examination and have the patient perform ankle pump exercises

D. Inform the physician immediately of the situation and discontinue the examination

D. Inform the physician immediately of the situation and discontinue the examination

A 65-year-old patient arrives comes to PT clinic. Patient reports that since morning, he has felt pain down both arms, has had shortness of breath, and has continued to perspire. What is the MOST appropriate intervention?

A. Evaluate the cervical spine and provide pectoral stretches to decrease bilateral arm pain.

B. Evaluate the cervical spine and provide scapular strengthening exercises to decrease bilateral arm pain.

C. Treat the patient with TENS and recommend that the patient follow up with a physician within 3 days.

D. Immediately contact emergency medical services.

D. Immediately contact emergency medical services.

Type I error

False positive

Type II error

False negative

SnOut

- The sensitivity describes the ability of a diagnostic test to identify true disease without missing anyone by leaving the disease undiagnosed.

- A highly sensitivity test has few false negatives and is effective at ruling conditions “out”

SpIn

- The specificity describes the ability of a diagnostic test to be correctly negative in the absence of disease without mislabeling anyone.

- A high specificity test has few false positives and is effective in ruling conditions “in”

A PT is using a new special screening test to help determine if a tennis player has a rotator cuff tear among other possibilities. The test has a very high sensitivity of 0.93 (or 93%). If the results of the test are negative, the PT should:

A. Try another special test for rotator cuff tear B. Consider the test results inconclusive

C. Rule in rotator cuff tear

D. Rule out rotator cuff tear

D. Rule out rotator cuff tear