Profile of brief symptom inventory-18 (BSI-18) scores in collegiate athletes: A CARE Consortium study

Objective: The goal of this study was to characterize normative scores for the Brief Symptom Inventory (BSI-18) in collegiate athletes to inform decision making about the need for psychological health services in this group. Methods: Collegiate student-athletes (N = 20,034) from 25 universities completed the BSI-18 at their preseason baseline assessment. A subgroup (n = 5,387) underwent multiple baseline assessments. Global Severity Index (GSI) scores were compared to community norms and across multiple timepoints. Results: Collegiate athletes reported significantly lower GSI scores than published community norms (ppn = 230; 1.15%). Conclusions: For collegiate student-athletes, published BSI-18 threshold scores identify only extreme outliers who might benefit from additional behavioral health evaluation. Alternatively, use of threshold scores ≥ the 90th percentile identifies a more realistic 11.4% of the population, with higher likelihood of prior concussion and/or psychiatric disorders.</p

Estimation of the limits of quantification (LOQ), based on the “Derivative” (A), the “Interval” (B), and the “Coefficient of Variation” methods (C).

<p>In A solid and dashed black lines show the standard curve and the second order derivative, respectively. Dashed blue lines show the limits of quantification. In B, solid and dashed red lines show the asymptote coefficients and the 95% confidence interval, respectively. Dashed blue lines show the LOQ, and dashed black lines show the 95% prediction interval of the standard curve. In C, solid red and black lines show the coefficient of variation (CV) estimated for each fitted concentration and the standard curve, respectively. Dashed blue lines show the LOQ, and the dashed black line shows the user specified CV cutoff.</p

Cartoon showing the influence of the Subtract method into the standard samples.

<p>Background noise calculated as the geometric mean of the blank controls is shown as a horizontal dashed line. (A) Standard curve plotting the MFI in the <u><b>original scale</b></u> as a function of concentration; (B) Standard curve plotting the MFI in the <u><b>original scale</b></u> as a function of concentration <u><b>after subtracting</b></u> the MFI of the blank control from all standard samples; (C) Standard curve plotting the MFI in the <u><b>log10 scale</b></u> as a function of concentration; and (D) Standard curve plotting the MFI in the <u><b>log10 scale</b></u> as a function of concentration <u><b>after subtracting</b></u> the MFI of the blank control from all standard samples.</p

Ranked log₁₀MAD of log₁₀MFI for the 16 combinations of the four assay conditions in the positive control.

<p>The x-axis shows the mean log₁₀MAD of log₁₀MFI and 95% confidence intervals. A) By antigen and B) Combining all antigens. The y-axis shows combinations of the following conditions, ordered by the value of the mean log₁₀MAD: temperature of sample-bead incubation (37 = 37°C and 22 = 22°C), sample predilution (D = daily and S = stock), beads coupling (S = single and C = three or more combined), and plate washing (A = automatic and M = manual).</p

Format of the input dataset used by the package.

<p>(A) Dataset user can create for the package; (B) package automated data management: datasets produced by the package when data is automatically extracted from the assay machine.</p

Standardized residuals as a function of the predicted base 10 logarithm median fluorescence intensity (MFI) for the four emulated datasets based on standard curves fitted using the four different approaches to treat background noise.

<p>Points outside of the range specified by the dashed lines are in red and labeled according to the well location in the 96-well plate. (A) Standard curve fitted using “Ignore” background noise method; (B) standard curve fitted including the background noise as an extra point when fitting the curve, using “Include” background method; (C) standard curve fitted subtracting the background noise using the “Subtract” method; (D) standard curve fitted constraining the lower asymptote to the background noise using the “Constraint” method.</p

Standard curves based on the four-parameter log-logistic model (FCT) fitted using the four alternative approaches to treat background noise (BKG) in the four emulated datasets.

<p>The dashed lines represent the confidence interval of the curve, and the green line represents the geometric mean of the blank controls. RS = R-square. (A) Standard curve fitted using “Ignore” background noise method; (B) standard curve fitted including the background noise as an extra point when fitting the curve, using “Include” background method; (C) standard curve fitted subtracting the background noise using the “Subtract” method; (D) standard curve fitted constraining the lower asymptote to the background noise using the “Constraint” method.</p

WHO reference standard curves against each of the antigens in the multiplex panel.

<p>Horizontal blue dashed lines represent the MFI quantification range (where the coefficient of variation is below 20%). The vertical black dashed lines encompass more reliable values of the assay output.</p

Linear regression models assessing the impact of combination of assay conditions on assay variability (log₁₀MAD of log₁₀MFI).

<p>Regression coefficients and p-values for one and two factors, all dilutions and antigens included. Bead coupling performed once at the beginning of the study (stock) or three times along the study (several); Sample predilution prepared at once (stock) or daily (daily); Sample-bead incubation temperature at 22°C or 37°C; Plate washing in an automated washer (automatic) or manually (manual); and Operator expertise, apprentice or expert. A) Positive control, 2 conditions, 8 dilutions and 7 antigens (N = 112); B) Subject samples, 2 conditions, 4 dilutions and 7 antigens (N = 56) and C) Multiplex blanks, 2 conditions and 7 antigen (N = 14). P-values adjusted for multiple testing by Benjamini & Hochberg (p-Adj). Significant p-values are shown in bold.</p

Antigen-specific log₁₀MFI levels of positive control serial dilutions by assay conditions.

<p>Spaghetti plots represent examples of positive control serial dilution MFIs against different antigens and in different assay conditions: Antigen-bead coupling (stock vs. several) for LSA-1; Sample predilution (stock vs. daily) for VAR2CSA; Temperature of sample-beads incubation (22°C vs. 37°C) for EBA-175 and Rh5; Plate washing (automatic vs. manual) for SSP2 and operator expertise (apprentice vs. expert) for MSP-1₄₂. Grey lines correspond to data from each plate.</p