Establishing Reliability When Multiple Examiners Evaluate a Single Case-Part II: Applications to Symptoms of Post-Traumatic Stress Disorder (PTSD)
Pages 35-47
Domenic Cicchetti, Alan Fontana and Donald Showalter
DOI: http://dx.doi.org/10.6000/1929-6029.2015.04.01.4
Published: 27 January 2015

Abstract: In an earlier article, the authors assessed the clinical significance of each of 19 Clinician Administered PTSD Scale items and composite scores (CAPS-1) [1] when 12 clinicians evaluated a Vietnam era veteran. A second patient was also evaluated by the same 12 clinicians and used for cross-validation purposes [2]. The objectives of this follow-up research are: (1) to describe and apply novel bio-statistical methods for establishing the statistical significance of these reliability estimates when the same 12 examiners evaluated each of the two Vietnam era patients. This approach is also utilized within the broader contexts of the ideographic and nomothetic conceptualizations to science, and the interplay between statistical and clinical or practical significance; (2) to detail the steps for applying the new methodology; and (3) to investigate whether the quality of the symptoms (frequency, intensity); item content; or specific clinician affect the levels of rater reliability. The more typical (nomothetic) reliability research design focuses on group averages and broader principles related to biomedical issues, rather than the focus on the individual case (ideographic approach). Both research designs (ideographic and nomothetic) have been incorporated in this follow-up research endeavor.

Estimating Mean and Standard Deviation from the Sample Size, Three Quartiles, Minimum, and Maximum
Pages 57-64
Martin Bland
DOI: http://dx.doi.org/10.6000/1929-6029.2015.04.01.6
Published: 27 January 2015

Abstract: Background: We sometimes want to include in a meta-analysis data from studies where results are presented as medians and ranges or interquartile ranges rather than as means and standard deviations. In this paper I extend a method of Hozo et al. to estimate mean and standard deviation from median, minimum, and maximum to the case where quartiles are also available.

Methods: Inequalities are developed for each observation using upper and lower limits derived from the minimum, the three quartiles, and the maximum. These are summed to give bounds for the sum and hence the mean of the observations, the average of these bounds in the estimate. A similar estimate is found for the sum of the observations squared and hence for the variance and standard deviation.

Results: For data from a Normal distribution, the extended method using quartiles gives good estimates of sample means but sample standard deviations are overestimated. For data from a Lognormal distribution, both sample mean and standard deviation are overestimated. Overestimation is worse for larger samples and for highly skewed parent distributions. The extended estimates using quartiles are always superior in both bias and precision to those without.

Conclusions: The estimates have the advantage of being extremely simple to carry out. I argue that as, in practice, such methods will be applied to small samples, the overestimation may not be a serious problem

Age Scale for Assessing Activities of Daily Living
Pages 48-56
Rafael Figueroa, Satoshi Seino, Noriko Yabushita, Yoshiro Okubo, Yosuke Osuka, Miyuki Nemoto, Songee Jung and Kiyoji Tanaka
DOI: http://dx.doi.org/10.6000/1929-6029.2015.04.01.5
Published: 27 January 2015

Abstract: The purpose of this study was to develop an age scale for assessing activities of daily living (ADL) among community-dwelling adults aged 75 years or older. Participants were 1006 older Japanese: 312 men (79.6 ± 4.3 years) and 694 women, (79.9 ± 5.5 years). Participants completed a battery of 8 performance tests related to ADL and the Barthel index (BI) questionnaire. Spearman rank-order correlation analysis was applied to obtain the correlation of the 8 ADL performance tests with the total BI score. Three variables were high rank-order correlated with BI, secondly those items were subjected to the principal component analysis. The weighted combination of the principal component scores was summed. Resulting in an ADL score (ADLS), women = 0.075 X₁ – 0.082 X₂ – 0.063 X₃ + 0.124, men = 0.051 X₁ – 0.105 X₂ – 0.099 X₃ + 0.249, where X₁ = hand-grip strength, X₂ = timed up and go, X₃ = five-chair sit to stand. Individual ADLS was transformed to an ADL age scale (ADLA). The estimation was – 5.493 ADLS + 79.90 for women, and – 4.272 ADLS + 79.57 for men. Due to the distortion at the regression edges, the equation was corrected as suggested by Dubina et al. ADLA women after correction was = 0.447 (chronological age: CA) – 5.49ADLS + 44.17, men = 0.519CA – 4.27ADLS + 38.26. ADLA can be used to identify or monitor the characteristics of the ADL levels of physical abilities in older Japanese aged 75 years or older.

An Exponential Melanoma Trend Model
Pages 65-71
Örjan Hallberg
DOI: http://dx.doi.org/10.6000/1929-6029.2015.04.01.7
Published: 27 January 2015

Abstract: The present study investigated whether whole population exposure to radiation introduced by radio broadcasting and cell phone systems might explain recent increases in melanoma trends in Nordic countries or not. Trends were modeled using a single exponential function of the time each age group has been living in the new environment since an environmental change took place. The results clearly show that melanoma incidences started to increase exponentially by the time lived as an adult since 1955 and that a second trend break occurred in 1997. We searched best fit between calculated and reported age-standardized rates by parameter variation, and compared calculated with reported age-specific rates without further parameter adjustments. Local variations of breast cancer, lung cancer and all cancers together significantly correlated with corresponding local melanoma rates in Sweden. Increasing cancer trends since around 1997 seem related to a population covering environmental change effective from early 90’s. We conclude that this exponential trend model can be a useful tool in understanding responses to sudden environmental changes.