Data distribution baseline pain VAS scores (average over 7 days).

<p>Data distribution baseline pain VAS scores (average over 7 days).</p

Standardised Response Means displayed by baseline raw pain VAS score.

<p>Inclusion criteria into the study included a minimum score on a single pain VAS of 30; although on the seven daily VAS measures some scored below 30 mm, these numbers were small. Standardised Response Means (SRM) data for those with daily measurs below 30 mm have therefore been combined into one group.</p

Person Item Threshold distribution (Pre VAS data).

<p>The graph displays the person-item threshold distribution map with the x-axes displaying location or difficulty of item thresholds (lower half) and location or level of pain reported on the VAS by participants (upper half). The y-axes display the frequencies of item thresholds (lower half) and participants (upper half). Thresholds of seven items are shown and it can be seen that the thresholds spread over 1½ logits only.</p

Vas conversion of raw (ordinal) data to interval data (item 4).

<p>* The range is from 0 to 50 as VAS scores have been halved, thus scores range from 0–50.</p

Visual analogue scale distribution at baseline and follow-up (averaged over 7 days).

<p>* The minimum baseline score is a little lower than 30 mm at screening, which took place a week before the commencement of the study.</p

Item Response Curve for one VAS item.

<p>The Item Response Curve displays the expected raw score on the y-axis and the interval transformed log score on the x-axis.</p

Data distribution follow-up pain VAS scores (average over 7 days).

<p>Data distribution follow-up pain VAS scores (average over 7 days).</p

Visual analogue scale item difficulty (pre-data).

<p>* The location represents the item difficulty in the Rasch model.</p

Boxplot comparing cut point of 9 on CES-D 13 with the original cut point of 16 on CES-D 20

<p><b>Copyright information:</b></p><p>Taken from "A longitudinal evaluation of the Center for Epidemiologic Studies-Depression scale (CES-D) in a Rheumatoid Arthritis Population using Rasch Analysis"</p><p>http://www.hqlo.com/content/5/1/41</p><p>Health and Quality of Life Outcomes 2007;5():41-41.</p><p>Published online 13 Jul 2007</p><p>PMCID:PMC1950699.</p><p></p> The recommended cut point of 9 is shown as a horizontal line

All metrics are equal, but some metrics are more equal than others: A systematic search and review on the use of the term ‘metric’

<div><p>Objective</p><p>To examine the use of the term ‘metric’ in health and social sciences’ literature, focusing on the interval scale implication of the term in Modern Test Theory (MTT).</p><p>Materials and methods</p><p>A systematic search and review on MTT studies including ‘metric’ or ‘interval scale’ was performed in the health and social sciences literature. The search was restricted to 2001–2005 and 2011–2015. A Text Mining algorithm was employed to operationalize the eligibility criteria and to explore the uses of ‘metric’. The paradigm of each included article (Rasch Measurement Theory (RMT), Item Response Theory (IRT) or both), as well as its type (Theoretical, Methodological, Teaching, Application, Miscellaneous) were determined. An inductive thematic analysis on the first three types was performed.</p><p>Results</p><p>70.6% of the 1337 included articles were allocated to RMT, and 68.4% were application papers. Among the number of uses of ‘metric’, it was predominantly a synonym of ‘scale’; as adjective, it referred to measurement or quantification. Three incompatible themes ‘only RMT/all MTT/no MTT models can provide interval measures’ were identified, but ‘interval scale’ was considerably more mentioned in RMT than in IRT.</p><p>Conclusion</p><p>‘Metric’ is used in many different ways, and there is no consensus on which MTT metric has interval scale properties. Nevertheless, when using the term ‘metric’, the authors should specify the level of the metric being used (ordinal, ordered, interval, ratio), and justify why according to them the metric is at that level.</p></div