Clinical question

Among children with motor performance problems, is The Motor Performance Checklist as accurate as the Bruininks-Oseretsky Test of Motor Proficiency for identifying developmental coordination disorder?

Search terms and databases used to find the evidence

Database: PubMed—Clinical Queries (with ‘diagnosis category’ and ‘narrow search’ selected)

Search terms: (The Motor Performance Checklist)

The PubMed clinical queries diagnosis ‘specific’ filter automatically combines this phrase with the term ‘specificity’ in the title or abstract. An alternative search approach would have been to enter this phrase in the CINAHL database and combine it with the term ‘specificity’. This search retrieves four titles. The second title is obviously relevant so you obtain the full text of the article.

Article chosen

Gwynne K, Blick B. Motor performance checklist for 5-year-olds: a tool for identifying children at risk of developmental co-ordination disorder. J Paediatr Child Health 2004; 40:369–373.

Structured abstract

Study design: This study used a cross-sectional design to compare a new measure of motor performance with a ‘gold standard’ test for identifying children with developmental coordination disorder.

Setting: The study was conducted in schools in Sydney, Australia.

Participants: All 5-year-old children in a random sample of seven schools from 59 primary schools in the northern beaches sector of Sydney were invited to participate. Of the total population of children in the participating schools, 141 (60%) participated in the study (mean age 5 years and 5 months; 54% male). The prevalence of developmental coordination disorder in the study population was 4.2%.

Description of test: The Motor Performance Checklist is a 12-item instrument for identifying children at risk of developmental coordination disorder.

Diagnostic standard: The Bruininks-Oseretsky Test of Motor Proficiency Long Form. A composite standard score of 40 (one standard deviation below the mean) was used as the Bruininks-Oseretsky Test of Motor Proficiency Long Form cut-off/failure point to direct children to occupational therapy.

Main results: The checklist was found to have a sensitivity of 83% and a specificity of 98%. Positive predictive validity was found to be 72% and negative predictive validity 99%.

Conclusion: The Motor Performance Checklist has the potential to aid in identifying children who are in need of referral to community occupational therapy services.

Is the evidence likely to be biased?

What are the main results?

In this study, 6 (4.2%) children were identified by the Bruininks-Oseretsky Test of Motor Proficiency as having developmental coordination disorder. This study presents the sensitivity, specificity, predictive values and likelihood ratios for identifying developmental coordination disorder using the Motor Performance Checklist (see Table 7.1) compared with the Bruininks-Oseretsky Test of Motor Proficiency Long Form using a cut-off score of 40 points.

TABLE 7.1 Ascertaining developmental coordination disorder

The Motor Performance Checklist has high specificity, which means that there would be very few false positives. The sensitivity of 83% is also reasonably high, meaning not many children who had developmental coordination disorder would be missed (few false negatives). The positive predictive value looks at the data in a different way: how to interpret the results for a given client whose true diagnosis we do not know when we have the test result. A positive predictive value of 72% means that we know the chance of a child having developmental coordination disorder after their score on the Motor Performance Checklist is positive is 72%. Similarly, based on the negative predictive value, the chance of their not having it after a negative test is better, at 99%. In other words, a negative test seems better at telling us the true diagnosis than a positive one. As you saw in Chapter 6, two things contribute to the predictive values: the quality of the test (how well it performs as described by the sensitivity and specificity) and the prevalence of the disorder. In this example only approximately 4% of children had the condition. This means that we can only generalise the predictive values to other populations that have similar condition prevalences.

Another way to deal with this is to use likelihood ratios, which use a clever algebraic approach enabling us not to have to rely on prevalence to describe the usefulness of a test, yet also employ both sensitivity and specificity. Thus the positive likelihood ratio is the likelihood of a positive test result in a child with the condition compared with the same likelihood in one without the condition. In this study the positive likelihood ratio is 41.5 [calculated as sensitivity ÷ (100 – specificity)]. Using the approximate guide values that were presented in Chapter 6, a positive likelihood ratio over 10 indicates that the test is extremely good for ruling in the presence of developmental coordination disorder if it is present. The negative likelihood ratio was 0.17 [calculated as (100 – sensitivity) ÷ specificity] which, again using the values presented in Chapter 6, indicates that it is a test that can also help rule out the presence of developmental coordination disorder.

How might we use this evidence to inform practice?

Although this study may be prone to some types of bias that are common in cross-sectional studies it was otherwise well-designed and you are reasonably confident about the results. There are three factors about this study to think about, though. First, the ability of The Motor Performance Checklist to identify children with developmental coordination disorder was restricted in this study to children who were 5 years old. Testing this measure with children from 4 to 10 years is needed as this is the age range that this assessment was designed to be used with. Second, the study reports a low prevalence of developmental coordination disorder and the authors state this is lower than reported in the literature. This means that, in populations with a higher prevalence of developmental coordination disorder, the positive predictive value (or the chance of the test being correct) will be greater than reported in this study. Finally, the brevity of this measure is appealing and the article also reports on the concurrent validity and reliability of this measure, which are other psychometric test properties that must be considered when considering using an assessment with clients. You think back to your original dilemma. Can you use The Motor Performance Checklist for identifying children with developmental coordination disorder? The results of this study are limited to children 5 years of age so, until further research is done that involves children of other ages, it may have limited, yet useful, value to your clinical practice.

Clinical question

In athletes with shoulder pain, is there a manual test for diagnosing posteroinferior lesions of the labrum and what is its diagnostic utility?

Search terms and databases used to find the evidence

Database: PubMed—Clinical Queries (with ‘diagnosis category’ and ‘narrow search’ selected)

Search terms: posteroinferior (labral OR labrum)

The search returns four records. One of these articles seems very promising: a comparison of the ability of two manual tests to diagnose posteroinferior labral tears, with surgical observation as the gold standard. It looks highly relevant but you are concerned that your search is too narrow. You repeat the search, selecting the ‘broad, sensitive search’ option. This returns 17 records, but none of these is as relevant as the original article that you found.

Article chosen

Kim S, Park J, Jeong W et al. The Kim test: a novel test for posteroinferior labral lesion of the shoulder—a comparison to the jerk test. Am J Sports Med 2005; 33:1188–1192.

Structured abstract

Study design: Cohort study.

Setting: Department of Orthopaedic Surgery at a hospital in Korea.

Participants: 172 adults awaiting arthroscopic examination for undiagnosed shoulder pain. Exclusion criteria were septic arthritis, fracture of the greater tuberosity, arthroscopic capsular release due to frozen shoulder, frozen shoulder and previous surgery.

Description of tests: For the Kim test, the client sits with the trunk against a backrest and the arm abducted to 90°. The examiner applies axial force along the humerus at the elbow to compress the glenohumeral joint and elevates the arm by 45°. With the other hand, the examiner applies downward and backward force to the upper arm. Sudden onset of pain indicates a positive test. For the jerk test, the client sits with the arm abducted to 90° and internally rotated 90°. The examiner stands behind and supports the scapula with one hand. With the other hand, axial force is applied at the elbow and maintained while the arm is horizontally adducted. Sharp pain indicates a positive test. Each test was performed by two independent examiners.

Diagnostic standard: Arthroscopic examination of the glenohumeral joint and subacromial space.

Main results: Thirty (17%) of the 172 participants had a posteroinferior labral lesion. The Kim test had sensitivity of 80% and specificity of 94%. The positive predictive value of the Kim test was 0.73 and the negative predictive value was 0.96. The jerk test had sensitivity of 73% and specificity of 98%. The positive predictive value of the jerk test was 0.88 and the negative predictive value was 0.95. The sensitivity in detecting a posteroinferior lesion increased to 97% when the two tests were combined.

Conclusion: The two tests, particularly in combination, have worthwhile clinical utility in the diagnosis of posteroinferior labral lesions.

Is the evidence likely to be biased?

What are the main results?

Thirty (17%) of the 172 participants had a posteroinferior labral lesion. The article presents the sensitivity, specificity, positive predictive value and negative predictive value of the two tests, which are shown in Table 7.2. You also use these results to calculate the positive and negative likelihood ratios (see Table 7.2).

TABLE 7.2 Results of the Kim test and jerk test

The positive predictive value of the Kim test indicates that, on average, 73% of people with a positive test result actually have a posteroinferior labral lesion. The positive predictive value of the jerk test indicates that, on average, 88% of people with a positive result actually have a posteroinferior labral lesion. Using the approximate guide values that were presented in Chapter 6, as both of the positive likelihood ratios are over 10, this indicates that these tests are very helpful for ruling in a posteroinferior labral lesion if it is present. Also, as the negative likelihood ratios are <0.5, this suggests that these tests are moderately helpful in ruling out a posteroinferior labral lesion.

How might we use this evidence to inform practice?

You are satisfied that the study is valid and the results are clinically useful. The study population was reasonably similar to the client to whom you are considering applying the tests, although in your practice not all clients are severe enough to be scheduled for arthroscopy, so the prevalence of posteroinferior labral lesions is likely to be lower. The tests can be performed quickly and without requiring specialised equipment. However, before applying these tests, you should consider other diagnoses. The client’s description of the location of the pain suggests that the posteroinferior labrum is involved. Furthermore, the following tests are negative: the apprehension test (for detecting anterior shoulder instability), the impingement test (for detecting rotator cuff inflammation or impingement), the horizontal adduction test (for assessing acromioclavicular joint impingement) and tests for superior labral lesions as mentioned in the clinical scenario. In doing this, you confirm that a posteroinferior labral lesion is the diagnosis that you primarily suspect. You decide to apply the Kim test and the jerk test to your client and use the results of these tests to guide the diagnosis and subsequent management of your client.

Clinical question

In a person with suspected tinea pedis is clinical presentation as accurate as microbiological confirmation for establishing the diagnosis?

Search terms and databases used to find the evidence

Database: PubMed—Clinical Queries (with ‘diagnosis category’ and ‘narrow search’ selected)

Search terms: Tinea OR ‘athletes foot’

You click on ‘Details’ to check how PubMed has processed your search and notice that it has automatically searched the Tinea MeSH term. This search retrieves 33 titles, so you start looking through them. Several studies look promising but, when you read through their abstracts, you find that they are either comparing different laboratory methods for diagnosing mycoses or are case-control studies. You know that case-control studies can overestimate the accuracy of diagnostic tests, so you reject these. There is one study that, on the basis of the abstract, appears to compare the clinical diagnosis of tinea pedis with laboratory methods but the operating characteristics of the tests are not reported. You are really only then left with one possible study. This study investigated the diagnostic value of signs and symptoms compared to culture for diagnosing dermatomycosis in general practice. You consider whether this study, which appears to have looked at the diagnosis of fungal infection on any hairless part of the body, could be relevant to your clinical situation. As there do not appear to be any studies that have looked specifically at the clinical diagnosis of tinea pedis, you obtain the full text of this study.