Table 2 Secondary outcomes

Number of sterilization cycles per procedure

• Mean number or sterilization cycles required per procedure

Set processing time in the OR

Consists of the following:

• Time taken to prepare (opening the set, preparing operating table and checking implants)

• Time taken to clean and remove systems in the OR (from removal of first implant from the OR to removal of all contaminated sets)

• Time taken to record implants used per procedure

• Time taken to replenish implants missing in the set

Set processing time in the sterilization department

Consists of the following:

• Time taken to wash all instruments and implants per set per procedure

• Time taken to assemble cleaning baskets per set per procedure

• Time taken for quality inspections before and after mechanical cleaning and assembly of the containers for sterilization per set per procedure

Set processing time in the purchasing department

Consists of the following:

• Time taken for validation and coding of the implants used per procedure

• Time taken for registration and re-coding time of the implants used per procedure

• Time taken to place an implant order per procedure

• Time taken to receive and reconciliate implants

• Time taken for manual error correction per procedure

Overall set processing time

• Sum of set processing time in the OR, sterilization department and purchasing department

Number of missing or damaged implants per procedure

• Total number or implants unavailable or damaged per procedure

Number of baskets used per procedure

• Number of baskets placed into the cleaning machine per procedure per cycle

Number of cleaning cycles per procedure

• Mean number of cleaning cycles required per procedure

Number of containers entering autoclave

• Mean number of containers entering the autoclave per procedure per cycle

Total set processing costs

Calculations based on the following:

• Each cycle (washing, sterilization and consumables) costs €18 (USD$19)

• Time costs calculated by costs of relevant workforce per time multiplied by average processing times

• Total cost calculated by the sum of the cost of cycles, cost of washing and sterilization time, cost of OR time and cost of purchasing department time

Water consumption and cost

Calculations based on the following:

• A water consumption of 60 L per cycle for the cleaning machine and 240 L per cycle for the autoclave

• Water consumption calculated as number of cleaning machine cycles multiplied by 60, plus the number of autoclave cycles multiplied by 240

• Costs were based on an average price of water for domestic use in Spain of 1.90 €/m3 (USD$2), as reported in the Asociación Española de Abastecimientos de Agua y Saneamiento—Asociación Española de Empresas Gestoras de los Servicios de Agua Urbana (AEAS-AGA) 2020 tariff survey(17)

Electricity consumption and cost

Calculations based on the following:

• An electricity consumption of 0.41 kW per cycle for the cleaning machine and 5 kW per cycle for the autoclave

• Electricity consumption calculated as number of cleaning machine cycles multiplied by 0.41, plus the number of autoclave cycles multiplied by 5

• Costs were based on an average price of €0.1214 (USD$0.1279) per kWh, as reported by FACUA in 2020(18)

Staff satisfaction

• Improvement by changing process assessed using a questionnaire

• NASA-TLX used to assess staff with physically demanding work