Description and validation of a test to evaluate sustained silent reading

Abstract

Purpose: To construct and validate a test of sustained silent reading.

Methods: Standardized 7300 and 7600 word passages were written to evaluate sustained silent reading. Two hundred forty subjects validated whether comprehension questions could discriminate subjects who did and did not read the passage. To evaluate test-retest properties, 49 subjects silently read the standardized passages on separate days. Sixty glaucoma suspect controls and 64 glaucoma subjects had their out loud reading evaluated with the MNRead card and an International Reading Speed Texts (IReST) passage, and their silent reading measured using the 7300 word passage. Sustained silent reading parameters included reading speed and reading speed slope over time.

Results: Comprehension questions distinguished individuals who had and had not read passage materials. Bland-Altman analyses of intersession sustained reading speed and reading speed slope demonstrated 95% coefficients of repeatability of 57 words per minute (wpm) and 2.76 wpm/minute. Sustained silent reading speed was less correlated with MNRead (r = 0.59) or IReST passage (r = 0.68) reading speeds than the correlation of these two measures of out loud reading speed with each other (r = 0.72). Sustained silent reading speed was more likely to differ from IReST reading speed by more than 50% in rapid silent readers (odds ratio [OR] = 29, 95% confidence interval [CI] = 10-87), and comparisons of sustained and out loud reading speeds demonstrated proportional error in Bland-Altman analyses.

Conclusions: Tests of out loud reading do not accurately reflect silent reading speed in individuals with normal vision or glaucoma. The described test offers a standardized way to evaluate the impact of eye disease and/or visual rehabilitation on sustained silent reading.

Conflict of interest statement

Disclosure: P.Y. Ramulu, None; B.K. Swenor, None; J.L. Jefferys, None; G.S. Rubin, None

Figures

Figure 1.

Bland-Altman analysis of reading parameters measured repeatedly. Repeated measures analyzed include sustained silent reading speed (A), out loud reading of IReST (B), and the slope of sustained silent reading speed (C). Sustained silent reading speeds and reading speed slopes were measured in a group of normally-sighted individuals reading the two sustained reading passages on several days. IReST reading speeds were compared in the same group of subjects for two IReST passages read on the same day. For each analysis, the mean difference is shown with a solid line, while the upper and lower limits of agreement, representing two SDs above and below the mean, are shown with dashed lines.

Figure 2.

Reading comprehension during the sustained reading test: distribution and relationship to the relative rate of silent and out loud reading. Reading comprehension is expressed as the percentage of comprehension questions answered correctly by a group of control and glaucoma subjects. The difference in sustained silent reading speed and out loud reading speed measured using an IReST was found to increase with the accuracy of reading comprehension.

Figure 3.

Bland-Altman analysis of reading speeds obtained using different tests. (A) Out loud reading speeds measured using an IReST and the MNRead card were compared. (B, C) Sustained silent reading speed was compared with IReST and MNRead reading speeds, respectively. Subjects include glaucoma subject controls with normal vision and glaucoma subjects with bilateral VF loss. For each analysis, the mean difference is shown with a solid line, while the upper and lower limits of agreement representing two SDs above and below the mean are shown with dashed lines.

Figure 4.

Difference between sustained silent reading speeds calculated for the full reading period and shorter durations. Differences were calculated as silent reading speed over the time duration shown minus the reading speed over the full reading period. Information was derived from older control and glaucoma subjects.

Figure 5.

Comparison of changes in silent reading speed as assessed over various durations of time. Information was derived from older subjects with and without glaucoma. All subjects read for 30 minutes or until all 7300 words were read. Information regarding shorter reading periods was taken from the first portion of their reading period. For example, the slope for 10′ of reading was taken from data corresponding to the first 10 minutes of each subject's sustained silent reading trial.