Ruff 2 and 7 Selective Attention Test: Normative data, discriminant validity and test retest reliability in Greek adults

Transcription

1 Archives of Clinical Neuropsychology 22 (2007) Ruff 2 and 7 Selective Attention Test: Normative data, discriminant validity and test retest reliability in Greek adults Lambros Messinis a,, Mary H. Kosmidis b, Ioanna Tsakona a, Vassilis Georgiou c, Eleni Aretouli b, Panagiotis Papathanasopoulos a a Department of Neurology, Neuropsychology Unit, University of Patras Medical School, Rion, Patras, Greece b Department of Psychology, Aristotle University of Thessaloniki, Greece c Departments of Mathematics and Statistics, University of Patras, Greece Accepted 6 June 2007 Abstract Rapidly expanding interest in neuropsychological assessment in Greece has made the development of appropriate culture-specific normative data for core neuropsychological measures essential. In the present study, we sought to establish normative, test retest reliability and discriminant validity data for the Ruff 2 and 7 Selective Attention Test in the Greek adult population. We administered the test using standard procedures to 218 healthy Greek adults (95 men), aged years and two adult patient groups (26 detoxified opiate addicts and 23 HIV seropositive individuals). Using linear regression analyses, we examined the contribution of age, education and gender on Ruff 2 and 7 performance. We further examined test retest reliability by administering the test on two occasions to 40 healthy adults, with an intersession interval of weeks. The regression analyses revealed that age and education, but not gender, contributed significantly to participants performance, with older age and lower education contributing to poorer performance on Speed scores, but only education contributing moderately to Automatic Detection Accuracy scores. Test retest reliability was very high (.94.98) for Speed scores, and adequate to high (.73.89) for Accuracy scores. Younger adults also demonstrated larger practice effects compared to older participants. The test appears to discriminate adequately between the performance of detoxified opiate addicts and HIV seropositive patients and matched healthy controls, as both patient groups performed more poorly than their respective control group. We present normative data for Speed and Accuracy scores stratified by age and education for the Greek adult population National Academy of Neuropsychology. Published by Elsevier Ltd. All rights reserved. Keywords: Ruff 2 and 7; Selective attention; Sustained attention; Greek normative data; Discriminant validity; Test retest reliability 1. Introduction Normative data are often used in clinical neuropsychological assessments as a means to determine the presence or absence of deficits, as well as the need for further diagnostic or assessment procedures. In Greece, interest in neuropsychological assessment is expanding rapidly, as the number of psychologists consulting clinically or involved in research in this area is increasing significantly. There has also been a large increase in the number of research Corresponding author. Tel.: /243; fax: address: lambros@hellasnet.gr (L. Messinis) /$ see front matter 2007 National Academy of Neuropsychology. Published by Elsevier Ltd. All rights reserved. doi: /j.acn

2 774 L. Messinis et al. / Archives of Clinical Neuropsychology 22 (2007) protocols utilizing neuropsychological test variables as outcome measures by other scientific disciplines, most notably, university-affiliated neurology and psychiatric clinics in collaboration with neuropsychologists. The increased demand for neuropsychological assessment in Greece and the lack of appropriate normative data have led neuropsychologists working in Greece to either develop appropriate new tests (Folia & Kosmidis, 2003; Kosmidis, Vlahou, Panagiotaki, & Kiosseoglou, 2004) or collect normative data for commonly used neuropsychological tests developed in other countries (Aretouli & Kosmidis, 2006, 2007a, 2007b; Argirokastritou, Samanda, & Messinis, 2005; Giannakou & Kosmidis, 2006; Kosmidis et al., 2004; Messinis, Lada et al., 2006; Messinis, Tsakona, & Papathanasopoulos, 2006; Vlahou & Kosmidis, 2002). Despite these important contributions in providing performance data for several core neuropsychological measures in the Greek population, appropriate norms for many other neuropsychological tests essential to the practicing clinician or researcher are lacking; therefore, the need to create culture-specific norms is evident. In this respect, we chose to provide performance data for a commonly used and relatively simple paper-and-pencil neuropsychological test of selective and sustained visual attention, the Ruff 2 and 7 Selective Attention Test (Ruff & Allen, 1996; Ruff, Evans, & Light, 1986). Deficits in attention are among the most common sequelae of brain damage following disease or injury and can have multiple negative influences on the lives of patients, possibly contributing to disability in activities of daily living (Cicerone & Azulay, 2002; Cohen, Malloy, & Jenkins, 1998; Kerns & Mateer, 1998; Weiss, 1996). Consequently, and despite current conceptual inconsistencies and lack of scientific agreement regarding the specific nature of attention in the literature, assessment of attentional functions constitutes an integral aspect of clinical neuropsychological assessments (Cohen et al., 1998). The 2 and 7 Selective Attention Test was developed to assess sustained and selective aspects of visual attention (Cicerone & Azulay, 2002; Ruff & Allen, 1996). The test is based on the premise that selective attention (i.e., the ability to select relevant stimuli while ignoring irrelevant information) can be assessed by comparing automatic detection versus controlled processing with minimal demands on other cognitive processes such as internal processing of information or immediate memory (Cicerone & Azulay, 2002). It is based on the theories of Logan et al. (Logan, 1988; Logan & Klapp, 1991; Logan & Stadler, 1991), which posit two processes through which attention is allocated: automatic information processing and effortful or controlled information processing (Strauss, Sherman, & Spreen, 2006). Two types of trials are presented in the test: Automatic Detection trials, in which the target numbers are presented among distractor letters, and Controlled Search trials, in which the target numbers are presented among other distractor numbers. Selecting targets from different stimulus categories represents parallel search or even automatic information processing. This categorical difference between letters and numbers is overlearned, and hence subject to automatic processing even in semiliterate individuals (Ruff & Allen, 1996). In contrast, selecting targets from the same stimulus category requires serial search or controlled information processing, i.e., working memory and effortful processing of stimulus characteristics are required to effectively select targets from distractors (Ruff & Allen, 1996; Ruff, Neiman, Allen, Farrow, & Wylie, 1992; Strauss et al., 2006). The actual 2 and 7 test is a paper-and-pencil number-cancellation task that consists of a set of 20 trials (10 Automatic Detection trials and 10 Controlled Search trials), presented semirandomly in the test booklet, with three lines per trial, administered consecutively in 15-s intervals. All instructions are provided verbally, and examinees are required to read through each line and cross out specific targets (always the numbers 2 and 7), working from left to right, while ignoring other letters or numbers (Ruff & Allen, 1996; Strauss et al., 2006). The total administration time after a brief practice set to assure that examinees understand the instructions is 5 min (Ruff & Allen, 1996). Several scores can be derived from the 2 and 7 test as described in detail in the test manual (Ruff & Allen, 1996). Scores are generally based on errors of omission (correct hits) and commission (incorrect responses). Selective attention is measured by the Automatic Detection and Controlled Search scores and sustained attention is measured primarily by the Total Speed (number of correctly identified targets during the allotted 5-min duration), and Total Accuracy (number of targets identified during the 5-min duration divided by the number of possible targets) scores. In the test manual several discrepancy analysis procedures are further provided in order to evaluate performance on various aspects of selective attention (Ruff & Allen, 1996). As regards the contribution of demographic variables on Ruff 2 and 7 performance, age has been found to correlate moderately with Automatic Detection Speed and Controlled Search Speed (r =.41 and.38, respectively; Ruff & Allen, 1996; Strauss et al., 2006). No significant effects of age have been reported in the literature on any of the accuracy variables (Strauss et al., 2006). Gender does not appear to influence performance on any of the test variables, as there are no reports of significant contributions of gender in the literature (Ruff & Allen, 1996; Strauss et al., 2006).

3 L. Messinis et al. / Archives of Clinical Neuropsychology 22 (2007) The literature regarding the specific contribution of formal education on Ruff 2 and 7 performance notes relatively small effects for Automatic Detection Speed and Controlled Search Speed (r =.19.24; Ruff & Allen, 1996; Strauss et al., 2006). Nevertheless, the contribution of education is sufficient to warrant education-based norms on these variables. Education does not appear to influence performance on any of the Accuracy scores, although higher levels of formal education may contribute to higher test retest gains on Speed scores (Lemay, Bedard, Rouleau, & Tremblay, 2004; Strauss et al., 2006). As regards the specific contribution of intelligence levels to Ruff 2 and 7 performance, negligible correlations with FSIQ have been reported (Ruff & Allen, 1996; Strauss et al., 2006). In contrast, modest correlations have been noted with PIQ when demographically corrected scores were utilized (r =.22.25; Strauss et al., 2006). Test retest reliability has been reported as adequate to high for the 2 and 7, with higher test retest coefficients reported for Speed than for Accuracy scores (Lemay et al., 2004; Ruff & Allen, 1996). The diagnostic utility of the test has been examined in patients with postconcussion syndrome (PCS) (Cicerone and Azulay, 2002). The authors reported strong positive predictive power for the Speed scores, indicating the diagnostic accuracy of impaired Speed scores for PCS patients. The 2 and 7 test has also been studied in other clinical populations, and appears sensitive to injury severity in both adults (Allen & Ruff, 1990; Bate, Mathias, & Crawford, 2001) and children with TBI (Nolin & Mathieu, 2001). Schizophrenic patients, on the other hand, demonstrate seriously compromised Speed scores independent of schizophrenia subtype (i.e., paranoid versus nonparanoid), but Accuracy scores appear less impaired (Weiss, 1996). Severe forms of depression appear to influence Total Speed scores selectively, but Total Accuracy scores to a lesser extent (Ruff & Allen, 1996; Strauss et al., 2006). The test s discriminant validity is reportedly adequate in discriminating between AIDS and AIDS-related complex patients (Schmitt et al., 1988). Few studies have explored the test s usefulness in localizing dysfunction. Despite suggestions that the Ruff 2 and 7 may differentiate between left-and-right hemisphere dysfunction, the evidence in this regard is limited (Ruff & Allen, 1996; Ruff et al., 1992; Strauss et al., 2006; Weiss, 1996). Instead, patients with frontal lesions may be distinguished from those with posterior lesions, given the former group s lower Accuracy score in the Controlled versus Automatic Detection Condition (Ruff & Allen, 1996; Strauss et al., 2006). Given the specific contributions of age and education on several Ruff 2 and 7 variables reported in the literature, and the absence of normative data for this test specific to the Greek population, we sought to investigate the demographic characteristics that influence performance on this test, and also to create norms based on these variables for the Greek adult population. We further examined the test s validity in discriminating adults with selective attention deficits, by assessing a sample of detoxified opiate addicts and a group of HIV seropositive patients as compared to age, gender and education-matched healthy control groups. Finally, we investigated test retest reliability and practice effects in a group of healthy Greek adults with a testing interval of weeks and present data stratified by age for Automatic Detection Speed, Controlled Search Speed, Automatic Detection Accuracy and Controlled Search Accuracy scores. 2. Method 2.1. Participants Two hundred and eighteen healthy Greek adults (95 men or 43.6%), recruited primarily from two large urban centers in Southwestern and Northern Greece (sample of convenience), participated in the present study voluntarily, and after providing written informed consent for their participation. Potential healthy participants were approached by the experimenters with the goal of including a broad range of adult ages and education levels. Healthy participants were years old (M = 45.07, S.D. = 17.45) and had 2 21 years of formal education (M = 13.01, S.D. = 4.20). Exclusion criteria were a history of psychiatric, neurological or cardiovascular disorders or of substance abuse or dependence (including alcohol and benzodiazepine abuse), a history of head injury or any other medical condition (including significant visual impairments not corrected sufficiently by visual aids) that might affect neuropsychological performance, and non-native speakers of the Greek language. We further excluded from the study of older adults (over 60 years), who on initial testing obtained scores of less than 27 on the Greek-validated version of the Mini Mental State Examination (MMSE; Fountoulakis, Tsolaki, Chantzi, & Kazis, 2000), a brief screening measure for global cognitive deficits. We also examined 26 detoxified heroine addicts, recruited from the detoxification and psychosocial substance rehabilitation program offered at the Merimna Life Care Unit in Athens, Greece (age: M = 30.35, S.D. = 7.04; level

4 776 L. Messinis et al. / Archives of Clinical Neuropsychology 22 (2007) of education: M = 10.96, S.D. = 2.40). As a group, these patients had a mean duration of heroine abuse of years (S.D. = 7.80) and a mean age of onset of years (S.D. = 7.82). They were heroine (opiate) free an average of days (S.D. = 31.08; range days). All participants in this group were diagnosed as persons with Opiod Dependence (DSM-IV-TR criteria; American Psychiatric Association, 2000), and were participating in an opiate detoxification rehabilitation program after having initially undergone an ultra rapid opiate detoxification procedure. Patients in this outpatient program receive naltrexone hydrochloride maintenance therapy at a dose of 50 mg/day (an opiate antagonist which is not addictive, and treats addiction at the receptor level instead of only withdrawing or substituting opiate agonists) and psychosocial support for a period of 12 months. We excluded participants from this group who met a current DSM-IV-TR diagnosis of dependence on any other drug or on alcohol, or suffered from any other medical condition that might affect neuropsychological performance, and non-native speakers of the Greek language. Participants in this group provided routine urine samples as part of their program requirements and before the neuropsychological testing session. A urinary toxicology screen further confirmed that no other illicit substances had been used by these participants following the detoxification procedure. We also examined a group of 23 HIV seropositive patients (13 asymptomatic and 10 symptomatic), who were recruited from the outpatient Infectious Diseases Unit, of AHEPA Hospital of the Aristotle University of Thessaloniki (age: M = 38.39, S.D. = 8.08; level of education: M = 13.91, S.D. = 2.75). As a group, these patients had a mean CD4 + T lymphocyte count of /mm 3, (S.D. = ) and 73.9% of the sample was on typical antiretroviral medication. Participants in this group were classified either as asymptomatic or symptomatic HIV seropositive patients using the Centers for Disease Control and Prevention HIV staging and classification system (Centers for Disease Control and Prevention [CDC], 1992). We excluded participants from this group who met a current DSM-IV-TR diagnosis of dependence on any drug or alcohol, those who were co-infected with Hepatitis C, and non-native speakers of the Greek language Procedure Healthy participants were initially screened through a standardized interview at the beginning of the testing session by the project staff clinical neuropsychologist and physician (in the Southwestern Greece sample) or the psychologist experimenter (in the Northern Greece sample), in order to exclude those with health problems or other exclusion criteria as described above. Participants over the age of 60 were also administered the Greek version of the MMSE (Fountoulakis et al., 2000). Detoxified opiate addicts were tested as part of a larger study examining the neuropsychological effects of naltrexone hydrochloride maintenance therapy in heroine addicts (Messinis, Tsakona et al., 2006). HIV seropositive patients were assessed at the outpatient Infectious Diseases Unit of AHEPA Hospital of Aristotle University of Thessaloniki, as part of a larger neuropsychological study examining cognition in the HIV/AIDS population in Greece (Messinis, Tsakona, Kollaras, Malefaki, & Papathanasopoulos, in press). The psychologists who served as experimenters had been trained intensively in the administration procedures of various neuropsychological measures, including the Ruff 2 and 7 Selective Attention Test, by doctoral level clinical neuropsychologists. The administration procedure used was that described in the test manual by Ruff and Allen (1996, pp. 5 6). The test requires participants to cross out target digits (2 and 7) working across the lines from left to right (i.e., one line at a time), by finding them among capital letters of the alphabet (automatic detection) or in blocks of digits (controlled search) in consecutive 15-s increments. Initially, a sample of each block consisting of three lines on the back of the test booklet was presented to the participant in order to ensure that the instructions were understood. If errors were made during these practice trials, e.g., errors of omission or commission, skipping a line or section or beginning a line from the right side of the page, the examiner pointed them out and emphasized the need for accuracy and speed. The participant was instructed to begin the search from the top left side of the line and to proceed to the second and third lines in a similar fashion. After completion of the sample trials, the participant was told that in the main part of the test similar blocks would be presented, requiring the participant to do what he or she had just practiced in the two trials. The participant was further told that after a brief time period the examiner would say Next, at which time the participant was to start a new block. Speed and accuracy of performance was again emphasized. The test commenced immediately following these instructions. Twenty blocks (10 for automatic detection and 10 for controlled search) of three lines with a time limit of 15 s per block were given. When extreme deviations occurred, the participants were corrected, without stopping the timing.

5 L. Messinis et al. / Archives of Clinical Neuropsychology 22 (2007) Statistical analysis We initially observed our data visually to determine whether the distributions met normality requirements. All data points that were considered outliers or extreme outliers were excluded from analyses (scores were considered outliers if they exceeded two standard deviations from the mean and extreme outliers if they exceeded three standard deviations from the mean). The normality assumption of our data was further investigated using the Kolmogorov Smirnov test for normality. Most of our variables were normally distributed; so parametric tests were mainly employed. In order to investigate the equality of means we used independent sample t-tests for normally distributed variables, and the Mann Whitney U-test for variables not normally distributed. In cases where statistically significant differences were found between the variances of groups, the t-test of unequal variances was used and the degree of freedom was estimated using the Welch Satterthwaite approximation. Levene s test was employed in order to investigate the equality of variances. Stepwise multiple linear regression analyses were used to examine the potential contribution of demographic variables (age, sex and years of formal education) to performance on the Ruff 2 and 7 scores. We also estimated test retest reliability by calculating Pearson product moment correlations between Search and Accuracy scores across two test sessions separated by a week time interval in a group of healthy participants grouped by age. Paired samples t-tests were used to compare means between the two sessions for Speed and Accuracy scores as these variables were normally distributed. The level of statistical significance was set at p=.05, and all analyses were conducted using the SPSS 14.0 software. 3. Results 3.1. Influence of demographic characteristics on Ruff 2 and 7 performance In order to examine the potential contribution of demographic characteristics to performance on the Ruff 2 and 7, we conducted linear regression analyses (Table 1). Results showed that age and education contributed significantly to performance on Automatic Detection Speed [F(3, 214) = , p = <.001], and Controlled Search Speed [F(3, 214) = , p = <.001]. On these trials, older participants with a lower education level, performed worse than younger participants with a higher educational level. Only education accounted for a significant proportion of the variance on the Automatic Detection Accuracy score [F(3, 214) = , p = <.001], and the Controlled Search Accuracy score showed a non-significant trend [F(3, 214) = 1.665, p =.052]. Participants with higher educational levels performed better than participants with lower levels of formal education. Given the significant contribution of age and education to the Automatic and Controlled Speed scores, the influence of education on the Accuracy scores as revealed by the regression analyses, and in order to obtain normative data for the Greek adult population, we grouped our sample into demographic categories. Graphs illustrating changes over the age range yielded three age groups: 17 39, and years old. We also grouped our sample based on the level of education so as to reflect school requirements in Greece (compulsory education is 9 years): 1 9, (high school) and 13 years and above (higher education including technological and other university level education). Table 2 presents means, standard deviations and percentile performance stratified by age and education level Discriminant validity In order to determine the validity of the Ruff 2 and 7 in discriminating patient groups from healthy participants, we compared 26 detoxified heroine addicts to 21 healthy controls, matched on sex ratio [x 2 (1) = 2.385, p =.122], level of education [Z = 1.779, p =.075] and age [t(45) =.641, p =.525]. Independent sample Mann Whitney U- tests revealed that the detoxified heroine addicts performed more poorly than the healthy controls on the Automatic Detection Speed score [Z = 1.980, p =.048] and the Automatic Detection Accuracy score [Z = 2.108, p =.035], but the groups did not differ on the Controlled Detection Speed and Controlled Detection Accuracy scores. Fig. 1 presents mean performance of the detoxified heroine addicts and the healthy group on the speed and accuracy dimensions of the Ruff 2 and 7. Similarly, we compared 23 HIV seropositive patients to a group of 27 healthy individuals, matched on sex ratio [x 2 (1) = 3.716, p =.054], level of education [Z =.423, p =.672] and age [t(48) =.62, p =.951]. Independent sample t-tests revealed that the HIV seropositive group performed more poorly than the healthy controls on the Automatic

6 778 L. Messinis et al. / Archives of Clinical Neuropsychology 22 (2007) Table 1 Linear regression analyses: Contributions of age, education and gender on Ruff 2 and 7 scores Score Variable B Std. error B t p R 2 ADS (Constant) < Age <.001 Education <.001 Gender ADE (Constant) Age Education Gender ADA (Constant) < Age Education <.001 Gender CSS (Constant) < Age <.001 Gender CSE (Constant) Age Education Gender CSA (Constant) < Age Gender Note: ADS, Automatic Detection Speed; ADE, Automatic Detection Error; ADA, Automatic Detection Accuracy; CSS, Controlled Search Speed; CSE, Controlled Search Errors; CSA, Controlled Search Accuracy. Detection Speed score [t(48) = 2.033, p =.048], Automatic Detection Accuracy score [t(48) = 2.039, p =.047] and Controlled Search Accuracy score [t(48) = 2.261, p =.029] of the Ruff 2 and 7, with no group difference on Controlled Detection Speed. Fig. 2 presents mean performance of the HIV seropositive patients and healthy group on the speed and accuracy dimensions of the Ruff 2 and Test retest reliability and practice effects A group of 40 Greek healthy adults (17 men or 42.5%), ranging in age from 20 to 71 years with a minimum 12 years of formal education completed (level of education: M = 15.05, S.D. = 2.85; range years), were administered the Ruff 2 and 7 on two occasions, with a testing interval of weeks in order to establish test retest reliability and to determine potential practice effects. Test retest means and reliability coefficients are presented separately for Automatic Detection and Controlled Search Speed, Automatic Detection and Controlled Search Accuracy scores, grouped by three age bands (20 39, 40 59, years old) (Table 3). Independent sample t-tests revealed that Speed scores were subject to a practice effect. Participants in all three age bands performed better on the second administration than the first on both Automatic Detection Speed [20 39 years old: t(15) = 5.702, p = <.001; years old: t(10) = 8.566, p = <.001; years old: t(12) = 6.895, p = <.001] and Controlled Search Speed scores [20 39 years old: t(15) = 9.725, p = <.001; years old: t(10) = 4.739, p = <.001; years old: t(12) = 3.339, p =.006]. For the Accuracy scores, significant practice effects were detected only for the age group on the Automatic Detection Accuracy [t(15) = 3.194, p =.006] and Controlled Search Accuracy scores [t(15) = 2.800, p =.029] of the Ruff 2 and Discussion Despite the widespread use of neuropsychological measures in clinical and research settings in Greece in recent years, normative data for commonly used neuropsychological tests remain largely unavailable. In an attempt to contribute

7 Table 2 Normative data stratified by age and level of education Age L. Messinis et al. / Archives of Clinical Neuropsychology 22 (2007) years years 60+ years Education (years) Education (years) Education (years) n =17 n =70 n =16 n =19 n =33 n =31 n =16 n =16 Automatic Detection Speed Percentile 5th th th th th M S.D Automatic Detection Accuracy Percentile 5th th th th th M S.D Controlled Search Speed Percentile 5th th th th th M S.D Controlled Search Accuracy Percentile 5th th th th th M S.D towards filling this gap, we developed culture-specific normative data for the Greek adult population of a useful and relatively simple paper-and-pencil neuropsychological test of selective and sustained visual attention, the Ruff 2 and 7 Selective Attention Test (Ruff & Allen, 1996; Ruff et al., 1986), stratified by those demographic characteristics that contributed significantly to performance on this test. We further provided data on the test s validity in discriminating adult patients with selective attention deficits, by comparing the Speed and Accuracy scores of detoxified opiate addicts on naltrexone maintenance therapy, and HIV seropositive patients to separate age, gender and educationmatched healthy control groups. Finally, we provided data for test retest reliability and practice effects in a group of 40 healthy Greek adults grouped by age with a testing interval of between 12 and 14 weeks, on Speed and Accuracy scores. To our knowledge there have been no attempts to date to develop normative data for the Ruff 2 and 7 in the adult population in Greece. Consistent with reports in the literature (Ruff & Allen, 1996; Ruff et al., 1986), our data showed that age accounted for a substantial proportion of the variance in Automatic Detection and Controlled Search Speed performance favoring younger healthy participants, i.e., a steady decline in performance was observed in Speed scores with increasing age

8 780 L. Messinis et al. / Archives of Clinical Neuropsychology 22 (2007) Fig. 1. Mean performance of the detoxified heroine addicts and the healthy group in the speed and accuracy variables of the Ruff 2 and 7. in a linear fashion, starting in young adulthood. No significant contributions of age were noted for any of the Accuracy scores, a finding that is also consistent with reports in the literature (Ruff & Allen, 1996; Ruff et al., 1986). Gender did not contribute significantly to any of the 2 and 7 scores, a finding that is consistent with the literature on the influence of this demographic variable on performance scores (Ruff & Allen, 1996). Reports regarding the effects of formal education on Ruff 2 and 7 performance have indicated that these are relatively small for Automatic Detection and Controlled Search Speed (Ruff & Allen, 1996). In contrast, we found that level Fig. 2. Mean performance of the HIV seropositive patients and healthy group in the speed and accuracy variables of the Ruff 2 and 7.

9 Table 3 Test retest means (S.D.), and reliability coefficients for Ruff 2 and 7 scores stratified by age Automatic Detection Speed Controlled Search Speed Automatic Detection Accuracy Controlled Search Accuracy Age group (years) Session 1 Session 2 r tt Session 1 Session 2 r tt Session 1 Session 2 r tt Session 1 Session 2 r tt (n = 16) (28.56) (27.82) (26.96) (27.19) (5.04) 95.7 (3.89) (9.19) 91.4 (7.43) (n = 11) (35.72) (36.81) (23.67) (25.67) (2.50) 96.2 (2.27) (4.24) 93.1 (3.20) (n = 13) (30.08) (30.47) (21.72) (22.22) (1.62) 96.5 (1.40) (5.01) 93.8 (3.73).76 Note: r tt, reliability coefficient. ownloaded from y guest n 24 July 2018 L. Messinis et al. / Archives of Clinical Neuropsychology 22 (2007)

10 782 L. Messinis et al. / Archives of Clinical Neuropsychology 22 (2007) of education contributed significantly to Automatic Detection and Controlled Search Speed Scores and to a lesser extent to Automatic Detection Accuracy scores. Participants with higher levels of education, but in similar age groups, outperformed participants with lower levels of education. Unlike previous reports (Ruff & Allen, 1996), our data demonstrated that education appears to influence Automatic Detection Accuracy moderately in addition to Speed scores. Our findings, unlike other studies (Ruff & Allen, 1996; Ruff et al., 1986) supporting the notion of relatively inconsistent and insignificant contributions of education to Ruff 2 and 7 performance, demonstrated that education is a substantial demographic contributor when making normative comparisons for this test. As regards the influence of intelligence levels on Ruff 2 and 7 performance, negligible to modest correlations with FSIQ and PIQ have been reported (Ruff & Allen, 1996; Strauss et al., 2006). In the present study, we did not examine the contribution of intelligence level to Ruff 2 and 7 performance in Greek adults for two reasons: First, there are no available standardized tests of intelligence in Greece for adults at present. 1 Second, we did not include intelligence level in our evaluations and analyses of our data for practical reasons related to the availability of IQ scores in Greek participants. If our data were found to be influenced by intelligence level, and thus stratified by this variable, this would require that participants tested with the Ruff 2 and 7 would also have to complete an intelligence test to establish Full Scale IQ, before the norms could be used adequately. In clinical outpatient settings, where most Greek adults with neuropsychological impairments are assessed, intelligence testing, which is highly time consuming and difficult to complete for certain patient groups, e.g., the elderly, the demented, people with sensory impairments etc., would prohibit the use of norms stratified by intelligence. Collectively, our data indicate that older participants with limited formal education, independent of gender, perform worse than younger participants, with a higher level of formal education on Automatic Detection and Controlled Search Speed. In addition, participants with high levels of education demonstrate better Automatic Detection Accuracy scores compared to those with low levels of education. Therefore, a steady and clear decline in Speed scores is evident with increased age and decreased education. At all ages and levels of education, more targets were identified in the Automatic Detection than in the Controlled Search condition. Having established the contribution of demographic characteristics to 2 and 7 performance, we then explored test retest reliability and practice effects of the test. In the literature, test retest reliability has been noted as adequate to high for the 2 and 7, with higher test retest coefficients reported for Speed than for Accuracy scores (Ruff & Allen, 1996; Lemay et al., 2004). Our data demonstrated excellent test retest reliability with high correlation coefficients (.94.98) for Speed scores and adequate to high coefficients (.73.89) for Accuracy scores. This finding is consistent with reliability data reported in the test manual (Ruff & Allen, 1996), and more recently by Lemay et al. (2004) as regards Speed scores. Our reliability coefficients regarding Accuracy scores, however, were higher than those reported either by Ruff and Allen (1996) or Lemay et al. (2004) (Table 3). Although our test retest interval of weeks is relatively shorter than the standardization sample interval of 6 months (Ruff & Allen, 1996), our opinion is that this is an adequate interval to obtain clinically useful test retest data. An advantage of our data regarding test retest reliability is the stratification of participants into three age groups starting from young adulthood to older participants over the age of 60, thereby providing important reliability data across the adult lifespan. Our data regarding potential practice effects on the 2 and 7 test showed that participants performance generally improved between the two test sessions. Younger adults demonstrated larger practice effects compared to older participants. More specifically, younger adults in the year old age group had a practice effect of about 11 raw-score points on Speed scores, compared to older adults over the age of 60, who showed a practice effect of about 4 raw-score points on Speed scores. Therefore, it appears that age significantly impacts the size of the practice effect on 2 and 7 Speed scores. Our findings are consistent with the preliminary data presented by Ruff et al. (1986), who demonstrated an increase of approximately 10 raw-score points between sessions for younger adults, and further replicate the more recently presented data of Lemay et al. (2004), who noted that Ruff 2 and 7 Speed scores were especially sensitive to practice effects. We were unable to replicate the findings of Lemay et al. (2004), however, regarding decreased test retest gains between the second and third test sessions, as we only assessed our participants twice. Regarding practice effects on the Accuracy scores, our data suggest low to moderate effects, a finding also supported by Ruff and 1 Research is currently being conducted at the Neuropsychological Laboratory of the Department of Neurology, University of Patras Medical School, in order to obtain normative data for the Wechsler Abbreviated Scale of Intelligence (Wechsler, 1999), a particularly useful and relatively brief measure of intelligence for clinical and research purposes (Messinis & Tsakona, 2006).

11 L. Messinis et al. / Archives of Clinical Neuropsychology 22 (2007) Allen (1996) in the test manual, and more recently by Lemay et al. (2004). Additionally, the present findings suggest that younger adults demonstrate significant test retest effects on Accuracy scores. This finding, however, will require replication in a larger young adult sample with lower levels of education, as our recruited group had a relatively high level of education (M = 15.05), as noted previously. With respect to the test s validity in discriminating specific patient groups with selective attention deficits from healthy individuals, our data demonstrated significant differences in performance between a group of HIV seropositive patients and healthy controls on Ruff 2 and 7 variables. More specifically, the HIV seropositive group achieved poorer scores than the healthy individuals on the Automatic Detection Speed, Automatic Detection Accuracy and Controlled Search Accuracy dimensions, but did not differ on Controlled Detection Speed. Findings of significantly lower Speed scores in AIDS compared to AIDS-related complex patients who were receiving Zidovudine (AZT) treatment for HIV infection have been reported in the HIV/AIDS literature (Schmitt et al., 1988). In the present study, Automatic Detection Speed and Accuracy scores adequately discriminated between HIV seropositive patients in less advanced stages of the disease process, as expressed by the relatively high CD4 + T lymphocyte counts of our HIV seropositive group (CDC, 1992), and healthy, demographically matched individuals. Our findings suggest that certain Ruff 2 and 7 scores are sensitive to neurological impairment caused by less advanced HIV infection, possibly related to frontostriatal neuropathology. The second group of patients assessed in order to establish the discriminant validity of the test was a group of detoxified heroine addicts who had remained abstinent for an average of 36 days, after having undergone an ultra rapid opiate detoxification procedure and was receiving naltrexone hydrochloride maintenance therapy. This group performed significantly worse than a demographically matched group of healthy individuals on Automatic Detection Speed and Automatic Detection Accuracy scores. This result suggests that the 2 and 7 Automatic Speed and Accuracy scores adequately discriminate performance of detoxified opiate addicts from matched healthy individuals. The above findings should, however, be interpreted with caution, as the abstinence period of the former heroine addicts was relatively short. It is possible that the performance of former heroine addicts might improve with larger abstinence periods. A possible confound of these data may be the potential influence of naltrexone hydrochloride maintenance therapy on test performance, although there are no reports in the literature that naltrexone may negatively impact neurocognitive functioning. Other possible explanations for the finding of lower performance in the detoxified opiate addicts include the direct toxic effects of a history of concomitant substance abuse, including adulterants, and/or the interactions of multiple drug abuse (Darke, Sims, McDonald, & Wickes, 2000). In evaluating the generalizability of the present results, several limiting factors need to be considered. First, the age and education stratified subgroups utilized in the study were not balanced in size. This is usually the case, however, in normative studies involving participants from a broad age range who were recruited from the community in a sample of convenience. Indeed, if one could achieve random sampling from the community, one would expect certain population trends to be reflected in the sample, i.e., a decrease in level of education as a function of increasing age. This is especially true for the Greek population, as many elderly people educated years ago have low levels of education, because they either did not attend school, left school early or did not attend a university or other higher educational institution, mainly for socioeconomic reasons (i.e., war, poverty). As a result, the sample sizes for certain subgroups are small (e.g., for elderly highly educated individuals and younger adults with limited education). Indeed, the absence of normative data for young adult participants in the age group, with 1 9 years of education is evident in our data. This caveat could not be avoided as we were unable to recruit participants with very low levels of education in either urban center in which we collected data, due mainly to formal schooling requirements in Greece, making a minimum of 9 years of education compulsory. One possible solution to small subgroup sizes is the use of broader age categories to increase the number of participants per subgroup. This strategy, however, may in turn cause problems related to the boundary values of the subgroups. Second, the relatively broad age range of our stratified subgroups may be a limiting factor, and this is especially true for the elderly participants. Elderly individuals typically show a more distinguishable pattern of performance decline with advancing age, and it would have been preferable to have used narrower groupings, e.g., 60 65, 66 69, 70 74, years old, etc. Third, a lack of familiarity with neuropsychological assessment procedures, which differ from traditional medical procedures to which elderly individuals in Greece have become accustomed, may have also influenced our findings. Examiners were, however, well trained in the administration of the Ruff 2 and 7, and had previous experience with elderly research participants. Significant efforts were made in order to ensure that these participants understood all administration procedures, therefore minimizing this possible limitation. A final limitation concerns the risk of sampling bias associated with motivation to participate in this study. It would appear

12 784 L. Messinis et al. / Archives of Clinical Neuropsychology 22 (2007) that healthy individuals willing to participate in the study are more motivated and possibly more curious about what a neuropsychological examination involves. It is also worth noting, however, that Greek participants were not paid for their participation in this study, therefore motivational issues related to the participants maximum output are speculative. Despite the potential limitations to the generalizability of the present normative data, the present study provides much needed performance data on a brief, psychometrically sound and clinically useful measure of selective and sustained attention on healthy adults and clinical groups specific to the Greek culture. The present findings serve as a reference point for the neuropsychological assessment of selective and sustained attention in the Greek population across the adult age range, with the exception of the older old. Further, it provides appropriate normative data, rather than having to inappropriately rely on U.S.-based norms or normative data used for English-speaking or other populations. Future research is desperately needed in order to provide normative data for the child and older old population in Greece, as normative data are generally lacking, not only in Greece, but internationally. Additional investigations to establish the relationship of the Ruff 2 and 7 Selective Attention Test to other measures of attention, e.g., Digit Symbol Modalities Test and other verbal and non-verbal core neuropsychological measures is also important. Finally, the diagnostic utility of the test warrants further exploration in clinical populations in Greece. Acknowledgements We would like to thank Dr. Dimitri Theodoroulea and the Merimna Life Care Unit in Athens, Greece for access to their patients, Theodore Paxino; Katerina Perrotti, Maria Diakou, Eleni Koutsonakou and Areti Metsovitou for their assistance with the data collection. References Allen, C. C., & Ruff, R. M. (1990). Self-Rating versus neuropsychological performance of moderate versus severe head-injured patients. Brain Injury, 4, American Psychiatric Association. (2000). DSM-IV-TR: Diagnostic and statistical manual of mental disorders (4th ed., Text Revision). Washington, DC: American Psychiatric Press. Aretouli, E., & Kosmidis, M. H. (2006, July). Cultural differences on Wisconsin Card Sorting Test performance: What do neuropsychological tests really measure? 26th International Congress on Applied Psychology, Athens. Aretouli, E., & Kosmidis, M. H. (2007, May). Are cancellation tests culture-free? Paper accepted to the 9th European Conference on Psychological Assessment & 2nd International Conference of the Psychological Society of Northern Greece. Aretouli, E., & Kosmidis, M. H. (2007, May). Rey Osterrieth Complex Figure Test: Greek norms and cultural and demographic influences. Paper accepted to the 9th European Conference on Psychological Assessment & 2nd International Conference of the Psychological Society of Northern Greece. Argirokastritou, E., Samanda, T., & Messinis, L. (2005, December). Preliminary normative data for the Symbol Digit Modalities Test (SDMT) in Greece. 10th Panhellenic Conference of Psychological Research, Ioannina, Greece. Bate, A. J., Mathias, J. L., & Crawford, J. R. (2001). Performance on the Test of Everyday Attention and standard tests of attention following severe traumatic brain injury. The Clinical Neuropsychologist, 15(3), Centers for Disease Control and Prevention. (1992). Revised classification system for HIV infection and expanded surveillance case definition for AIDS among adolescents and adults. Morbidity and Mortality Weekly Report, 41, Cicerone, K. D., & Azulay, J. (2002). Diagnostic utility of attention measures in postconcussion syndrome. The Clinical Neuropsychologist, 16(3), Cohen, R. A., Malloy, P. F., & Jenkins, M. A. (1998). Disorders of attention. In P. J. Snyder & P. D. Nussbaum (Eds.), Clinical neuropsychology: A pocket handbook for assessment (pp ). Washington, DC: American Psychological Association. Darke, S., Sims, J., McDonald, S., & Wickes, W. (2000). Cognitive impairment among methadone maintenance patients. Addiction, 95, Folia, V., & Kosmidis, M. H. (2003). Assessment of memory skills in illiterates: Strategy differences or test artifacts? The Clinical Neuropsychologist, 17, Fountoulakis, K. N., Tsolaki, M., Chantzi, H., & Kazis, A. (2000). Mini Mental State Examination (MMSE): A validation study in Greece. American Journal of Alzheimer s Disease and Other Dementias, 15, Giannakou, M., & Kosmidis, M. H. (2006). Cultural appropriateness of the Hooper Visual Organization Test? Greek normative data. Journal of Clinical and Experimental Neuropsychology, 28, Kerns, K. A., & Mateer, C. A. (1998). Walking and chewing gum: The impact of attentional capacity on everyday activities. In R. J. Sbordone & C. Long (Eds.), Ecological validity of neuropsychological testing (pp ). Boca Raton, FL: St. Lucie. Kosmidis, M. H., Vlahou, C. H., Panagiotaki, P., & Kiosseoglou, G. (2004). The verbal fluency task in the Greek population: Normative data and clustering and switching strategies. Journal of the International Neuropsychological Society, 10,