Cancelacion DVT(6y9)

Archivesof ClinicalNeuropsychology.Vol.1I, No.4, pp. 339-344.1996 Pergamon Copyright© 1996NationalAcademyof Neuropsychology Printedin the USA.All rightsreserved 0887-6177/96$15.00+ .00 SSDI 0887-6177(95)00032-1 The Digit Vigilance Test: Reliability, Validity, and Sensitivity to Diazepam Donna Z. Kelland Manchester, New Hampshire Ronald F. Lewis Center for Forensic Psychiatry, Ann Arbor, Michigan The Digit Vigilance Test (DVT), a measure of sustained attention and psychomotor speed, was eval- uated in terms of test-retest and alternate-form reliability as well as sensitivity to a single dose of diazepam (10 rag). A one-page version was compared to the standard two-page format. Forty undergraduates, randomly assigned in a double-blind manner to either drug or placebo condition, were tested three times in two sessions (1 week apart). Both Page I and Total Time scores were found to be highly reliable across time and forms. Repeated measures ANOVAs revealed the Total Time score, but not the Page I score, to be significant in discriminating diazepam from placebo across time, supporting the use of the complete D V T f o r measuring drug effects. Findings based on convergent measures also help to validate the D VT as a measure of sastained attention. The Digit Vigilance test (DVT; Lewis & Rennick, 1979) is a test of sustained attention and psychomotor speed for which extensive norms are available (Heaton, Grant, & Matthews, 1991; Lewis, Kelland, & Kupke, 1990). The DVT has been used widely to study a number of neurological conditions (e.g., Grant, Prigatano, Heaton, McSweeney, Wright, & Adams, 1987; Rosene, Copass, Kastner, Nolan, & Eschenbach, 1982), including different stages of HIV infection (Heaton et al., 1995), and psychotropic interventions (e.g., Novelly, Schwartz, Mattson, & Cramer, 1986; Samquist, Schoene, Hackett, & Townes, 1986; Townes, Dikmen, Bledsoe, Hornbein, Martin, & Janesheski, 1986). In an earlier report on the same study, we described the inability of the DVT, as part of a larger battery, to significantly discriminate diazepam versus placebo on the basis of an end-point measurement (Kelland & Lewis, 1994). This was disappointing in that numerous studies have identified the negative influence The authors thank Dr. David Gurevitch for his medical supervision and overall assistance in this project. The Digit Vigilance Test (1995) is available for purchase from Psychological Assessment Resources, Inc., Odessa, FL 33556. National norms for the Digit Vigilance Test (Heaton, Grant, & Matthews, 1991) are also available from Psychological Assessment Resources, Inc. Address correspondence to: Ronald E Lewis, Center for Forensic Psychiatry, P.O. Box 2060, Ann Arbor, MI 48106. 339 aged 18-30 years.0. These groups were comparable (Student's t-test) in terms of mean years of age (diazepam = 19. Ghoneim. 1984. & Hinrichs. Ghoneim. Furthermore. & Hinrichs. SD = 15. SD = 1.340 D. a caffeine survey of potential volunteers was used to select moderate caffeine users. and learning and memory (e. Mewaldt. Kelland and R. Lewis & Rennick. SD = 1. 1994). placebo = 69. attention.8). cardiac. and randomly assigned in a double-blind manner to either placebo or drug condition to manipulate arousal level for the final DVT administration. we are expanding on the earlier report by further examining the sex effect reported on the DVT. Because differences in caffeine consumption levels can affect task performance and modify effects of diazepam. placebo = 20. Subjects who typically drank more than two cups of coffee each day were not accepted. or hepatic disease. we described a significant sex by session effect for the DVT in terms of errors. recruited from a large urban university.1. in subjects who received oral diazepam as compared to those who received placebo. & Kupke.7. 1979). and weight in kilograms (diazepam = 73. cognition. using a modified administration format. In addition. In contribution toward further understanding of the psychometric properties of the DVT.4. Subjects were tested three times in two session. placebo = 13.3.3. Subjects were free from any history of neurological. as well as from psychiatric illness. Z. The subjects were matched for sex and randomly assigned in a double-blind manner to either diazepam or placebo condition for the final test administration. Lewis. the Discriminant Reaction Time Test (DRAT) and Visual Analogue Sedation Ratings (VASRs. E Lewis of diazepam on psychomotor performance. who had a history of alcohol or drug abuse. Previously. 1 week apart. SD = 9.3. Berchou & Block.3). SD = 2. METHOD Subjects The sample consisted of 40 (20 female) healthy. convergent validity is assessed with tasks previously demonstrated to be sensitive to diazepam: namely. paid volunteers.6.. females made more errors with practice (baseline to predrug trial) and males made less errors (Kelland. Rich and Brown (1992) reported a significant within-subject decrement in Digit Vigilance. This self-report served to screen out subjects who were taking medication.g. or whose medical history contraindicated use of CNS-depressant drugs. Subjects were asked to cross out as quickly as possible a specific target number (6 or 9) that appears ran- domly within 59 rows of 35 single digits on two pages. years of education (diazepam = 13. Mewaldt. in the current report. 1986). SD = 1. the present study reports additional data and examines the ability of the DVT to discrimi- nate a single. Tasks The DVT was presented as part of a larger battery of attention/psychomotor tests (the Repeatable Cognitive-Perceptual-Motor Battery. clinically relevant dose of diazepam (10 mg) from placebo in a repeated mea- sures format. Those who responded were contacted for a tele- phone screening interview prior to acceptance into the study. renal.9). The present study also compares the reliability and sensitivity data for the standard two- page test with that of an abbreviated one-page version. 1983).1. that is. The examiner observes the subject's performance on the demonstration rows and then on the first five rows of the test to deter- mine whether corrective feedback is required to discourage an inefficient or poorly motivat- . 01. For the first (practice) administration. They were instructed to indicate the current strength of their feeling of alertness or drowsiness by placing a mark at any point along the line.39). subjects again completed the VASR. Subjects first completed the VASRs.66. p < .p = . repeated measures ANOVAs of error scores revealed no significant group by session interaction for either page 1 errors (F = . 11). p < . p = . with repeated con- trasts revealing a significant decrease in total time between trial 1 and trial 2 (F = 20. Procedure Each subject was tested three times in two sessions separated by 1 week and conducted at the same time of day to avoid within-subject diurnal variation in performance.01. the other half were administered forms 9 and 6. respectively. subjects orally ingested 10 mg diazepam or a placebo capsule identical in appearance.80. p < . For the Visual Analogue Sedation Rating (VASR). test-retest reliability coefficients of error scores were also significantly high (n = 40. p < . total time score was more sensitive to the sedative effects of diazepam than was page 1 time. The beginning of the second session was identical to the first: subjects completed the VASR and then the DVT. Then. page 1 time: r = . The subject is instructed to press a key whenever the digit "4" is presented. r = .77. p < .05) for the total time. p = .39.62.13. Evaluation of the DVT 341 ed response style (e. ratings were recorded for a MENTALLY SLOW/ MENTALLY Q U I C K continuum. In a similar manner. Stimulus presentation is adjusted based on performance.90.14. and various other tests.01). but not between trial 2 and trial 3 ( F = 2. each subject was presented with a 100 m m line scale labeled ALERT at one end and D R O W S Y at the other.01).30) or error (F = 2.61. random sequence over a 50-second interval. That is.10. Half the subjects received diazepam and half received placebo. resulting in a rapidly obtained threshold-type measure. Lewis & Rennick.01). The DVT was administered once in the first session to reduce practice effects and to provide a base- line for reliability data.01) as well as for page 1 time (n = 40.72. DRAT. RESULTS Results indicate high test-retest reliability (1-week interval) of the DVT for both the total time (n = 40. Single digits (1 to 7) are presented in a rapid.01). Following a 30-minute intermission. p < . p = . p = ..vs. suggesting the rela- tive insensitivity of DVT error scores to psychotropic effects. p < . 1979) is a computer- controlled measure of sustained attention and discriminant reaction time. The Discriminant Reaction Time Test (DRAT.74. going too fast and missing numbers or going too slow and focusing attention on each individual number). Total time and errors o f omission were recorded. R = . total errors: r = . postdrug) interaction (F = 4.93.54) or for total errors (F = . and then the DVT as part of the larger battery identified above. but not for page 1 time (F = 2. repeated measures A N O V A s indicated a significant group (diazepam versus placebo) by session (pre. Furthermore. p < . p < . all subjects were asked to complete the standard format (target = 6). As shown in Figure 1. The position of this mark (in millimeters from the left end of the scale) was measured.38.91.g.16). . and then in counterbalanced order the DVT.01). Likewise. Half o f the subjects (n = 20) were administered form 6 for the second adminis- tration and form 9 for the third. Alternate form reliability was also significantly high for both scores (n = 20. total time: r = . page 1 errors: r = . There were no significant sex by administration interactions for either the total time (F = 1. Repeated measures ANOVA of practice effects across the three DVT administrations for the placebo subjects (see Table 1) was significant (F = 11. 38) or total time (r = .503. Finally. Kelland and R. The finding that DVT total time discriminated the drug conditions. 1983) . repeated administration may serve to reduce the novelty and sensitivity of the neuropsychological task.01 vs.1 SD 57. Furthermore.. more generally. it did correlate sig- nificantly with DVT total errors (r = .65) or error (F = 1.18).01). may minimize practice effects and intersubject variability. p = . Other measures previously found sensitive to diazepam .6 289. supports the use of the complete test for measuring drug effects and also helps to validate the DVT as a measure of sustained attention or vigilance.43. The sensitivity of these quick and easily obtained rating mea- surements warrant further investigation. the DRAT significantly discriminated the diazepam from placebo group (t = 2.to significantly discriminate earlier stages of HIV infection from a later stage. whereas the DVT had been administered twice previously. differvs. The sex by administration difference found between administrations 1 and 2 was not observed between administrations 2 and 3. E Lewis TABLE 1 Mean DVT Total Time Score Across Adminhtrations (n = 20. but page 1 time did not.. Heaton et al. p < . In contrast to the DVT.81. the effect did not persist beyond the second administration or that the effect was spurious. the DVT was found to be highly reliable with respect to both test-retest and alternate form reliability for both page 1 and total time scores.01) and the Mentally SlowfMentally Quick VASR (F = 6.16) scores. it is true that an initial practice session or. the Alert/Drowsy VASR (F = 23. n. similar to the DVT total time score.44. VASR measurements were very sensitive to the sedative effects of diazepam. Although the DRAT.05. 7.01) significantly discriminated between placebo and drug conditions across administrations. . DISCUSSION In summary.DRAT and VASRs (Berchou & Block.2 49. suggesting either that. Error scores were also found to be reliable. It may be.05). administrationI. administrationIlL p = . p < .2 *p < .0" 292. however. On the other hand.36) scores.13.. which was administered in the final postdrug session only. On the one hand.were again sensitive to diazepam and supported the convergent validity of the DVT as a measure of psychotropic effects. especially because these cost-effective subjective measures have been largely overlooked by both clinical and research neuropsychologists. only the DVT total time score significantly dis- criminated a clinically relevant dose of diazepam from placebo across time. however. the DRAT significantly discriminated the groups based on an end- point administration. that the ability of the DRAT to discern between drug conditions depended on its novelty.. Of these variables. This identification of a significant reduction in sensitivity from original to short version may serve to increase awareness of the potential generalizabili- ty of this trend in the use of other neuropsychological tests with a significant attentional com- ponent. p < . In fact.but not the DVT error score . p < . did not significantly correlate with DVT page 1 (r = . (1995) reported the DVT total time score . a repeated measures format.342 D.. p = . Placebo Subjects) Administration I II HI DVT total time Mean 314.s. Furthermore. Similar to the current fmdings.1 68. there were no significant group by sex interactions for either the time (F = . & Block. e3 150. we can conclude that the current study provides support for the DVT as a measure of change for sustained attention/psychomotor speed. 57. I. (1983). REFERENCES Berchou.. . Leaving aside these more abstract considerations. 01) The diazepam group demonstrated a significant increase in mean DVT total time as compared to the placebo group. R. 691-700. 120 II III Administration 13 DIGIT VIGILANCE Total 320" Q--@ placebo A--A diozepam 510" 13 0 0 . Perceptual and Motor Skills. R. This inherent trade-off may be worthy of empirical exploration as well as being an important consideration in the design of studies of drug responsiveness or changes in other psychoU-opic factors. Evaluation of the D VT 343 DIGIT VIGILANCE Page 1 180- @--@ placebo A--A diazepam 170- 160. Use of computerized psychomotor testing in determining CNS effects of drugs. ~D E 1#0- FT- 130.500" E 1= 290- A 280 II III Ad m[n ist ratio n FIGURE 1. (A) Mean DVT Page 1 score did not significantly discriminate groups across admin~tratlom. D. R. Z. G. I. J. H.. R. R. R.. 65. Prigatano. J. & Townes. Wright. M. 88. Grant. (1986).. 1. M. & Cramer. White.. A. Abramson. S. Hesselink. & Lewis. A. M. K. J. and Janesheski. & Rennick. & Matthews. R. L. FL: Psychological Assessment Resources. Lewis. Mewaldt. A.. Velin. Inc. and clinical applications. L.. R. (1995). A. and Environmental Medicine. Kelland. Dikmen. Sex differences on first and second administrations of the Repeatable Cognitive-Perceptual-Motor Battery.. K. healthy population after controlled hypotensive anesthesia. D. Evaluation of the reliability and validity of the Repeatable Cognitive- Perceptual-Motor Battery. Comprehensive norms for an Extended Halstead-Reitan battery: Demographic corrections.. Martin. Persistent neuropsycho- logical sequelae of toxic shock syndrome.. Novelly.. D. 999-1006. 313-317. Psychopharmacology.. 955-959. K.. Odessa. MI: Axon. Bledsoe. Copass.. T.. D. and The HNRC Group. & Hinrichs. M. 82. (1990). Aviation. McSweeney. G. Kelly... N. (1992). E H.. S. Z. The Clinical Nearopsychologist.. Space. Kelland and R. T. E. S. G. E. Kastner. K. Z. R. & Hinrichs. & Eschenbach. 96. Schoene. Kelland. R. 201. Journal of International Nearopsychological Society. D. & Kupke. 44. D. 296-300. 331-340. Psychopharmacology (Berlin). Manual for the Repeatable Cognitive-Perceptual-Motor Battery. T.. A. & Brown. M.. E. (1986).. G. 5. M. A normative study of the Repeatable Cognitive-Perceptual-Motor Battery.. V.Neuropsychology of HIV infec- tion at differenct disease stages. Annals of Internal Medicine. A... P. M. E Lewis Ghoneim. M. J. (1984). 8.. T. P.. D.. cognition and mood. J. K. The HNRC 500 . Townes. M. Grant. Wallace. Lewis. J. 865-870. W. S. Z. C.. I. B. Butters. Heaton. E (1994).. D... Jernigan. Epilepsia. C.. Sarnquist. M. & Adams. Archives ofClihical Neuropsychology. Archives of General Psychiatry. P. E. J. Marcotte. R. Heaton. D. R. M. D. Taylor. A. R. 148. I. Dose-response analysis of the behavioral effects of diazepam II: Psychomotor performance.. J. Progressive neuropsychologic impairment and hypoxemia. M. Schwartz. Rosene. Heaton. Psychopharmacology (Berlin). H. 295-308. B. C. T. 231-251. Selective dissociations of sedation and amnesia following ingestion of diazepam.... D. 57.. Grosse Point. 27. K. Nolan. C. T. I. Lewis. Kelland. (1986). (1991). Wolfson. Mattson. 165-171. J. Rich. S. B. Hornbein. 346-350. S.. Behavioral toxicity associated with antiepileptic drugs: Concepts and methods of assessment. J. R.. Ghoneim. J. P. Hemodilution of polycythemic moan- taineers: Effects on exercise and mental function. Anesthesia and Analgesia. researchfindings.. R. 106. 0982). H. Haekett. Archives of Clinical Neuropsychology. Atldnson. Neuropsychological changes in a young. J. (1994). (I 979). Ellis. Chandler.344 D.. M. McCutchen. A.. Grant. 9. P.. The behavioral actions of diazepam and oxazepam are similar.. Kirson. & Kupke.. (1987). C. Mewaldt. (1986). .