Perception of patient safety differs by clinical area and discipline

BACKGROUND

Current thinking about patient safety emphasizes the relationship between organizational factors, that is, latent risk factors (LRFs) and patient safety. This study explores the influence of the operating theatre (OT), intensive care unit (ICU), and disciplines on ratings of LRFs. If we have an understanding of the contribution made by these factors, we can identify significant points from which we can promote a safe environment.

METHODS

Staff in four university hospitals were sent a survey relating to the state of LRFs, which included communication, planning and coordination, design, maintenance, equipment, teamwork, team instructions, housekeeping, situational awareness, hierarchy, and procedures.

RESULTS

The ICU staff had more favourable perceptions of training, communication, team instruction, and hierarchy. The OT staff had more favourable perceptions of technical LRFs. We found three profiles for disciplines: (i) anaesthetists and intensivists had more favourable perceptions of technical LRFs than surgeons and nurses. (ii) Anaesthetists, anaesthesia nurse-technicians, and recovery nurses had a poorer perception of non-technical skills. (iii) Anaesthesia nurse-technicians and recovery nurses had less favourable perceptions of procedures, housekeeping, and situational awareness than anaesthetists and intensivists.

CONCLUSIONS

As healthcare focuses its safety efforts towards system issues rather than towards the individual provider of care, attention has turned to organizational factors, known as LRFs. Understanding how LRFs affect safety should enable us to design more effective measures that will improve overall safety. Strategies for improving patient safety should be tailored specifically for various clinical areas and disciplines.

Patient safety: latent risk factors

The person-centred analysis and prevention approach has long dominated proposals to improve patient safety in healthcare. In this approach, the focus is on the individual responsible for making an error. An alternative is the systems-centred approach, in which attention is paid to the organizational factors that create precursors for individual errors. This approach assumes that since humans are fallible, systems must be designed to prevent humans from making errors or to be tolerant to those errors. The questions raised by this approach might, for example, include asking why an individual had specific gaps in their knowledge, experience, or ability. The systems approach focuses on working conditions rather than on errors of individuals, as the likelihood of specific errors increases with unfavourable conditions. Since the factors that promote errors are not directly visible in the working environment, they are described as latent risk factors (LRFs). Safety failures in anaesthesia, in particular, and medicine, in general, result from multiple unfavourable LRFs, so we propose that effective interventions require that attention is paid to interactions between multiple factors and actors. Understanding how LRFs affect safety can enable us to design more effective control measures that will impact significantly on both individual performance and patient outcomes.

The detection of anisochrony in monaural and interaural sound sequences

Nakao and Axelrod (1976) and van Noorden (1975) showed that the threshold for discriminating an anisochronous duple rhythm (a series of clicks with a temporal offset on every other one) from an isochronous rhythm (no offset) is poorer when the clicks are presented alternately to the two ears than when they are presented to the same ears. Van Noorden reported that the difference between the thresholds in the alternating and nonalternating conditions varied with the tempo of the sequence. Nakao and Axelrod found invariance of this threshold difference with sequence speed. According to our quantification of temporal processing of interaural sequences, the latter result should be expected. We carried out five psychophysical experiments to establish interaural and monaural discrimination between isochronous and anisochronous rhythms. Across experiments, base time intervals of 60-720 msec were spanned. The main result was that we replicated the poorer discrimination for interaural sequences. This deterioration in discrimination was the same for all sequence speeds. It was also the case that the thresholds were almost constant up to a sound repetition rate of about 3 per second, but increased linearly with slower rates. This result supports evidence in the literature that temporal processing of sequences faster than about 3-4 sounds per second differs from temporal processing of slower sequences.

Auditory spatial alternation transforms auditory time

Recent research has shown that a sequence of auditory events that is alternated between the ears is stretched out in auditory memory, as compared with nonalternating sequences. Although the stimulus-onset asynchronies (SOAs) of the interaural and monaural sequences were the same, the perceptual-onset asynchronies (POAs) differed by 24 msec. Because this result was only established for a restricted range of SOAs (125-250 msec), the present study tested a much larger range (40-2,130 msec). It turned out that the POA difference of 25 msec remained invariant over this whole range. Furthermore it was investigated how the angle of alternation affected the POA difference. It was found that (a) this difference increased linearly with increasing angular separation, and (b) the effects of SOA and angular separation on the POA difference were additive. The merits of six different attention-switching models were inspected to explain these results, but none of the models could describe the effects satisfactorily. We offer a new model, the space-time network, that copes not only with the present results but also explains several other studies reported in the literature.