Deciding whether a new test/measure is useful

Reliability of overbite depth indicator (ODI) and anteroposterior dysplasia indicator (APDI) in the assessment of different vertical and sagittal dental malocclusions: a receiver operating characteristic (ROC) analysis

Introduction:

Differential diagnosis of skeletal and dental relationships is crucial for planning orthodontic treatment. Overbite depth indicator (ODI) and anteroposterior dysplasia indicator (APDI) had been introduced in the past for assessment of vertical and sagittal jaw relationships, respectively.

Objective:

The objectives of this study were to evaluate the reliability of ODI and APDI in overbite and Angle malocclusions, as well as assess their diagnostic reliability among males and females of different age groups.

Material and Methods:

This study was conducted using pretreatment dental casts and lateral cephalograms of 90 subjects. For ODI, subjects were divided into three groups based on overbite (normal overbite, open bite and deep bite). Likewise, the same subjects were divided for APDI into three groups, based on Angle's malocclusion classification (dental Class I, II and III malocclusions). Mann-Whitney U test was applied for comparison of study parameters regarding sex and different age groups. The mean values of ODI and APDI were compared among study groups by means of Kruskal-Wallis and post-hoc Dunnet T3 tests. The receiver operating characteristic (ROC) curve was applied to test diagnostic reliability.

Results:

Insignificant differences were found for ODI and APDI angles, particularly in regards to sex and age. Significant intergroup differences were found in different overbite groups and Angle's classification for ODI and APDI, respectively (p < 0.001). ROC showed 91% and 88% constancy with dental pattern in ODI and APDI, respectively.

Conclusions:

ODI can reliably differentiate deep bite versus normal overbite and deep bite versus open bite. APDI can reliably differentiate dental Class I, II and III malocclusions.

The need to address the burden of musculoskeletal conditions

Musculoskeletal conditions are common in men and women of all ages across all socio-demographic strata of society. They are the most common cause of severe long-term pain and physical disability and affect hundreds of millions of people around the world. They impact on all aspects of life through pain and by limiting activities of daily living typically by affecting dexterity and mobility. They affect one in four adults across Europe [1]. Musculoskeletal conditions have an enormous economic impact on society through both direct health expenditure related to treating the sequelae of the conditions and indirectly through loss of productivity. The prevalence of many of these conditions increases markedly with age, and many are affected by lifestyle factors, such as obesity and lack of physical activity. The burden of these conditions is therefore predicted to increase, in particular in developing countries. The impact on individuals and society of the major musculoskeletal conditions is reviewed and effective prevention, treatment and rehabilitation considered. The need to recognise musculoskeletal conditions as a global public health priority is discussed.

Determination of Class II and Class III skeletal patterns: receiver operating characteristic (ROC) analysis on various cephalometric measurements

Receiver operating characteristic analysis is an excellent method for evaluating and comparing the performance of diagnostic tests. The purpose of this study was to use the receiver operating characteristic analysis to evaluate the diagnostic ability of several cephalometric measurements in determining the presence of Class II and Class III skeletal patterns. Receiver operating characteristic analysis was performed on 976 cases. Fifteen cephalometric measurements were evaluated. A computer software program ROC ANALYZER was used to tabulate the areas under the curves and to perform the statistical comparison between the curves. The results of this study indicated that the Anteroposterior Dysplasia Indicator had the best diagnostic ability in identifying cases with Class II and Class III skeletal patterns. WITS Appraisal and Overjet were highly effective in diagnosing cases with Class II skeletal pattern. WITS Appraisal, Convexity, AB Plane Angle and Overjet also performed well in diagnosing cases with Class III skeletal pattern.

Cost effectiveness of periodontal services

This paper presents the combined use of decision trees and cost-effectiveness analysis to determine on which patients new diagnostic tests can be useful, and whether they can change the dentist's decision to provide different services and thus improve patient outcomes in 5 different categories of patients. A decision tree is constructed in which the primary decision branches are "test" and "no test". The treatment and outcome branches in the test branch are affected by the results of the test which is then either negative or positive. In contrast, the treatment and outcome branches in the no-test branch represent pathways for patient therapy when the new (or additional) test is not used. Results show that even with excellent test efficacy parameters (sensitivity 0.87 and specificity 0.84) it is not cost effective to use a diagnostic test in the general population or for adults under age 45 years. However for adults > 45 years, patients referred to a periodontist, and patients with a history of periodontal disease, the test would change treatment decisions and improve patient care outcomes.

A summated score for the medication appropriateness index: development and assessment of clinimetric properties including content validity

Inappropriate medication prescribing is an important problem in the elderly, but is difficult to measure. As part of a randomized controlled trial to evaluate the effectiveness of a pharmacist intervention among elderly veterans using many medications, we developed the Medication Appropriateness Index (MAI), which uses implicit criteria to measure elements of appropriate prescribing. This paper describes the development and validation of a weighting scheme used to produce a single summated MAI score per medication. Using this weighting scheme, two clinical pharmacists rated 105 medications prescribed to 10 elderly veterans from a general medicine clinic. The summated score demonstrated acceptable reliability (intraclass correlation co-efficient = 0.74). In addition, the summated MAI adequately reflected the putative heterogeneity in prescribing appropriateness among 1644 medications prescribed to 208 elderly veterans in the same general medicine clinic. These data support the content validity of the summated MAI. The MAI appears to be a relatively reliable, valid measure of prescribing appropriateness and may be useful for research studies, quality improvement programs, and patient care.

Evaluating diagnostic tests

The presentations at this conference will discuss new technologies and rapid scientific developments that have resulted in new diagnostic tests for periodontal disease, musculoskeletal imaging, temporomandibular joint dysfunctions, and incipient coronal and root dental caries. However, for many of these claims, there has been insufficient scientific support regarding the sensitivity and specificity of the tests, or their ability to predict the percent of cases in which the disease or condition progresses to the next state of development. Research is needed that will yield the basic diagnostic parameters of new diagnostic tests, i.e., their accuracy, precision, sensitivity, specificity, positive predictive value, and negative predictive value. The purpose and methods for calculating each of these measures are described in this paper. Five questions are then presented that will need to be addressed in future research regarding new diagnostic tests: (1) Does the scientific theory of the test fit with our current body of knowledge? (2) Have the efficacy parameters of the test been reliably determined? (3) How does the test affect clinical decision-making? (4) Does using the test improve the patient's health? and (5) Is the added expense of the test justified by increased effectiveness or by avoiding other health expenditures?