Table 1. Study characteristics. Details of each study with regards to: country where study was conducted, length of study, sample size (n), main quality improvement (QI) technique used and outcome of study.
| References | Country and length | n | Main intervention stated | Outcomes |
|---|---|---|---|---|
| Al-Hakim et al., 2012 | Australia, 5 months | 31 | Lean principles (included time and motion principles, process charts, motion economy) | Preventable disruption accounts for 25% increase in surgical time |
| Attarian et al., 2013 | USA, 3 years | DNS | Six Sigma principles (included DMAIC) | OT start increased from <60% to >90%; average turnover time decreased by 25 minutes; average number of cases per OT increased by 29% |
| Berber et al., 2002 | USA, DNS | 33 | Time and efficiency analysis technique | Surgical steps that took statistically longer were identified |
| Berber et al., 2001 | USA, ?4 years (stated 1994–1997) | 48 | Time and efficiency analysis technique | Longer operating times identified in specific clinical situations |
| Cima et al., 2011 | USA, 6 months | Pre-implementation: specialty 1, 735; specialty 2, 1,740; specialty 3, 1,685 |
Lean and Six Sigma principles (included process mapping and value stream mapping) | Statistically significant improvement in on-time starts, reduction in non-operative time, increase in percentage of OTs closed at 5 p.m., reduction in staff overtime |
| Post-implementation: specialty 1, 2,430; specialty 2, 2,430; specialty 3, 1,907 | ||||
| Collar et al., 2012 | USA, 18 months | Before: 35; after: 55 | Lean principles | Significantly shorter mean turnover time and turnaround time; improved staff morale after implementation; surgical trainee education unchanged |
| Damle et al., 2016 | USA, 7 months | Before: 107; after: 110 | Lean principles | Statistically significant decrease in mean colonoscopy time by 10%; overall colonoscopy unit capacity increased from 39.6 to 43.6 per day |
| Harewood et al., 2008 | Ireland, 5 weeks | 400 | Time-motion approach | Efficiency quotient increased with four separate interventions by up to 63.3% |
| Lee et al., 2008 | Israel, 4 years (stated 2005–2008) | 100 | Harvard Business School Model | Mean operative time for both unilateral and bilateral DIEP flap breast reconstruction decreased, with no change in complication rate; statistically significant improvement in prophylactic heparin administration; antibiotic administration and redosing of antibiotics trended upwards; improved interdisciplinary communication, transition guidelines, and enhanced efficiency |
| Marsh et al., 2016 | UK, 12 months | 163 | Process mapping | Increased overall efficiency in DIEP flap breast reconstruction, achieving three operations in one theatre in 1 day, compared to one operation previously |
| McLaughlin et al., 2014 | USA, DNS | 124 (total across two different groups) | Time-driven activity-based costing (included process mapping) | Pilot study which identified average cost capacities for personnel in theatre |
| Minekus et al., 2005 | Netherlands, DNS | 40 | Time-action analysis | Identified large variations in duration of shoulder joint replacement operations, tasks for team members, and approach used; identified factors which influenced operation (the prosthesis, the surgical approach, surgeon experience, and patient condition); main limitations identified as repeated actions and waiting time |
| Schwarz et al., 2011 | Germany, ?3 years (stated 2008–2010) | Before: 42; after: 75 | Value stream mapping (VSM) | Decrease in mean throughput time in colonoscopy unit, with corresponding decrease in patient waiting time by 23% |
| Tebbetts, 2002 | USA, 5 years | Before: group 1, 16; group 2, 16; after: 627 |
Time and motion study principles | Anaesthetic, operative and postanaesthetic care times decreased significantly |
| Toro et al., 2015 | USA, DNS | 30 | Analysis of a stepwise technique | Identified: mean operative time as the step with the least time variance, longest step, step with greatest time variance |
| Warner et al., 2015 | USA, 12 months | 127 | VSM, DMAIC, Lean Six Sigma principles, process redesign | Reduced mean technical costs of endovascular aneurysm repair by 10%, reduced instrument use by 39% |
| Warner et al., 2013 | USA, 1 year and 9 weeks (stated follow-up period to 1 year from implementation) | Before: 62; after: 926 | Lean Six Sigma principles | 32% increase in first case on-time starts, with a sustained 86% on-time start rate at 1-year follow-up |
DMAIC, define, measure, analyze, improve and control; DNS, did not state; OT, operating theatres; DIEP, deep inferior epigastric perforator.