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. Author manuscript; available in PMC: 2019 Feb 1.
Published in final edited form as: Int J Audiol. 2017 Dec 7;57(SUP1):S3–S11. doi: 10.1080/14992027.2017.1410237

Table 3.

Unadjusted models for predicting percentage of age-corrected and non-age-corrected standard threshold shifts (STS) at metal manufacturing facilities in the US (N=14).

Per Person Cost (USD) Age-corrected STS1 (%) Non-Age-Corrected STS1 (%) High-Frequency Hearing Loss Rate2 (dB/year) Hearing Impairment3 (%)
Variables β SE P β SE p β SE p β SE p
Total costs 0.001 0.005 0.782 −0.003 0.008 0.716 0.001 0.001 0.207 0.027 0.024 0.263
Cost by wages vs. non-wages
    Wages 0.002 0.006 0.692 −0.001 0.010 0.892 <0.001 0.001 0.827 0.003 0.032 0.926
    Non-wages 0.000 0.006 0.961 −0.004 0.012 0.719 0.001 0.001 0.120 0.050 0.033 0.130
Cost by program element4
    Program management 0.004 0.007 0.577 0.002 0.013 0.875 0.001 0.001 0.141 0.039 0.039 0.313
    Audiometry 0.000 0.011 0.999 0.025 0.018 0.158 <0.001 0.002 0.908 −0.010 0.058 0.861
    Workers Comp Claims −0.001 0.009 0.930 −0.006 0.016 0.675 0.002 0.001 0.191 0.012 0.048 0.803
    HPDs −0.001 0.009 0.945 −0.011 0.015 0.454 0.001 0.001 0.604 0.090 0.041 0.026*
    Training −0.004 0.027 0.871 −0.063 0.047 0.178 −0.006 0.004 0.112 −0.274 0.133 0.040*
    Fit-testing −0.095 0.048 0.045* −0.239 0.074 0.001*** −0.010 0.007 0.161 −0.339 0.285 0.233
    Training + fit-testing −0.023 0.024 0.332 −0.098 0.035 0.006** −0.007 0.003 0.029* −0.283 0.111 0.011*
    Industrial hygiene 0.028 0.025 0.259 −0.002 0.046 0.964 0.001 0.004 0.749 −0.133 0.138 0.333
    Hearing loss investigation −0.021 0.035 0.549 0.031 0.063 0.619 −0.005 0.005 0.333 0.150 0.190 0.428
    Equipment 0.018 0.077 0.813 −0.034 0.140 0.805 −0.12 0.011 0.280 −0.605 0.398 0.128
    CAOHC5 certifications 0.204 0.063 0.001*** 0.147 0.146 0.314 0.010 0.012 0.379 −0.125 0.462 0.788
1

Standard Threshold Shift, as defined by the Occupational Safety and Health Administration, averaged over the five years preceding the site evaluation.

2

Average threshold loss per year at 3000, 4000, and 6000 Hz over the ten years preceding our site evaluation. If the facility’s hearing conservation program was under ten years old, then all available years of data were used.

3

Hearing impairment as defined by the American Medical Association for the most recent year available at the time of the site evaluation.

4

Corporate software descriptives not included due to standardized prices across facilities; however, corporate software costs are included in total costs and non-wage costs in statistics above, but were otherwise not used for predictive modelling.

5

Council for the Accreditation of Occupational Hearing Conservationists.

*

Significant at the 0.05 α level

**

Significant at the 0.01 α level

***

Significant at the Bonferonni-corrected α level of 0.004