Table 3

Respiratory symptoms and airway inflammation associated with specific medical instrument cleaning and disinfection tasks in tertiary hospital health workers

n (%)Asthma symptom score†Asthma symptom score (≥2 vs 0–1)WRONSWRASFeNO, ppb‡ (n=654)FeNO≥50 ppb
(n=654)
Prevalence (%) (n=697)91 (13)109 (16)48 (7)41 (6)
Medical instruments cleaning and disinfection301 (43)
Medical instruments cleaning and disinfecting tasks§331 (48)1.14 (0.84 to 1.55)1.14 (0.71 to 1.84)1.24 (0.79 to 1.94)1.01 (0.54 to 1.89)1.07 (0.97 to 1.18)1.49 (0.74 to 3.01)
Manually disassembling instruments, removing/flushing gross contaminants
 Yes versus no201 (29)1.35 (1.00 to 1.84)1.26 (0.77 to 2.04)1.13 (0.71 to 1.79)1.16 (0.60 to 2.22) 1.12 (1.01 to 1.25)* 1.74 (0.86 to 3.50)
  0 min/week496 (71)111111
  1–99 min/week133 (19)1.40 (0.98 to 1.99)1.36 (0.78 to 2.35)0.82 (0.46 to 1.47)1.23 (0.58 to 2.63) 1.15 (1.02 to 1.30)* 2.00 (0.91 to 4.38)
  ≥100 min/week68 (10)1.27 (0.80 to 2.03)1.07 (0.49 to 2.31)1.80 (0.97 to 3.37)1.04 (0.38 to 2.80)1.07 (0.91 to 1.26)1.29 (0.42 to 3.96)
Diluting or mixing cleaning products
 Yes versus no251 (36)1.08 (0.80 to 1.46)0.98 (0.61 to 1.58)1.39 (0.89 to 2.17)1.02 (0.54 to 1.93)1.01 (0.92 to 1.12)1.26 (0.63 to 2.52)
  0 min/week446 (64)111111
  1–99 min/week213 (31)1.10 (0.80 to 1.50)1.02 (0.62 to 1.67)1.37 (0.86 to 2.18)1.06 (0.54 to 2.05)0.99 (0.89 to 1.10)1.23 (0.59 to 2.53)
  ≥100 min/week38 (5)1.00 (0.54 to 1.86)0.82 (0.30 to 2.26)1.53 (0.63 to 3.75)0.80 (0.18 to 3.60)1.16 (0.94 to 1.44)1.49 (0.39 to 5.69)
Changing sterilisation solutions
 Yes versus no157 (23)1.38 (1.00 to 1.92)1.32 (0.78 to 2.23)1.53 (0.95 to 2.45)0.78 (0.36 to 1.66)1.04 (0.93 to 1.16)1.28 (0.59 to 2.74)
  0 min/week540 (78)111111
  1–99 min/week135 (19) 1.48 (1.05 to 2.08)* 1.53 (0.89 to 2.63)1.23 (0.73 to 2.08)0.77 (0.35 to 1.72)1.03 (0.91 to 1.16)1.41 (0.63 to 3.13)
  ≥100 min/week22 (3)0.80 (0.34 to 1.93)0.33 (0.04 to 2.52) 4.44 (1.70 to 11.62)** 0.80 (0.10 to 6.34)1.13 (0.86 to 1.48)0.66 (0.08 to 5.75)
Manually sterilise/disinfection of medical instruments
 Yes versus no143 (21)1.30 (0.92 to 1.84)1.25 (0.72 to 2.16)1.35 (0.79 to 2.28)1.05 (0.47 to 2.31)1.09 (0.97 to 1.23)1.42 (0.64 to 3.17)
  0 min/week554 (80)111111
  1–99 min/week106 (15)1.36 (0.93 to 2.00)1.33 (0.73 to 2.41)0.94 (0.49 to 1.79)0.92 (0.37 to 2.33)1.08 (0.95 to 1.24)1.75 (0.76 to 4.06)
  ≥100 min/week37 (5)1.11 (0.59 to 2.06)1.03 (0.38 to 2.84) 2.92 (1.33 to 6.41)** 1.42 (0.40 to 5.03)1.11 (0.89 to 1.39)0.52 (0.07 to 4.20)
Sterilise medical instruments using automated systems
 Yes versus no15 (2)1.56 (0.65 to 3.70)2.30 (0.68 to 7.77)1.70 (0.45 to 6.37)3.62 (0.72 to 18.26)1.19 (0.87 to 1.63)1.79 (0.33 to 9.62)
  0 min/week682 (98)111111
  1–99 min/week8 (1)NCNCNCNCNCNC
  ≥100 min/week7 (1)NCNCNCNCNCNC

  • Data are presented as OR (95% CI), unless otherwise indicated.

  • Adjusted for atopy, gender, smoking, age, study site and allergic sensitisation to natural rubber latex.

  • Bold values denote statistical significance at p<0.05 level.

  • *p<0.05, **p<0.01.

  • †Mean ratio (95% CI).

  • ‡Geometric mean ratio (95% CI).

  • §A combined variable consisting of 5 tasks involved in medical instruments cleaning and disinfection, that is, precleaning of instruments by removing/flushing gross contaminants, diluting/mixing cleaning products, changing sterilisation solutions, manually sterilise/disinfection of medical instruments and sterilise medical instruments using automated systems.

  • FeNO, fractional exhaled nitric oxide; NC, not calculable; WRAS, work-related asthma symptoms; WRONS, work-related ocular-nasal symptoms.