Now that you have a more thorough understanding of quantitative methods (i.e., descriptive statistics, correlations, other statistical tests), which do you believe holds more promise to the Management

Studies may be carried out using quantitative methods of less rigour, but the possibility of erro- neous conclusions increases the further one moves from the classical prospective study. All too often, nothing is done at all, with the result that much of our professional activity continues to be empirically based. There are some constraints which are peculiar to quantitative research. An a priori hypothesis is required; this may limit the chance of a truly new ®nding. Indeed, Claude Bernard taught that new information usually lay in ªoutliersº of data sets, not in the body of infor- mation substantiating a hypothesis. 2Another dis- advantage is that values must often be reduced to numbers using measurement techniques which may only capture one facet of a multi-faceted phenomenon. However, the main constraint of quantitative research may be that studies of adequate design may be so expensive to set up and dif®cult to run, that nothing at all is done.

Qualitative research has its own set of applica- tions and limitations. It may be particularly useful where problems are ªcomplex, contextual and in¯uenced by the interaction of physical, psycho- logical and social factorsº 2; it would thus seem well suited to probing the complex factors behind human error and system failure. Unconstrained by the need to reduce the data to a set of numbers, qualitative research may allow phenomena to be studied from more perspectives and in greater depth; it may also allow studies to be more easily carried out in a normal environment and during routine work. In this sense, qualitative research lends itself to a naturalistic approach.

Data collection methods include observation, inter- views, focus groups, questionnaires, narratives and video- and audio-tape recordings. 3 The incident reporting study described in this symposium exploited several of the advantages inherent to qualitative research. Its overall struc- ture was relatively unconstrained as anaesthetists were asked to report ªany unintended incident which did, or could have reduced the safety mar- gin for a patientº. It used a questionnaire with both unstructured (free narrative) and structured components (to reliably ®nd out, for example, which monitors were in use). The data were then classi®ed according to the task in hand (e.g.

de®ning the role of monitors, testing the validity of an algorithm). Established methods were used to test reliability and validity, e.g. inter-observer reliability, concurrent validity (where one method of research yields similar results to another) and construct validity (such that observations are consistent with current theory). 3±5 ªGood qualitative research should give answers which are plausible, ®t other evidence that we are aware of, be convincing, and should have the power to change practice.º 3The incident monitor- ing study reported in this symposium provides a comprehensive qualitative picture of current clini- cal anaesthetic practice, and is a powerful tool for ªcontinuous quality improvementº at ªgrass- rootsº level. Its use is entirely consistent with the philosophy of ªkaizenºÐªcontinuous improve- ment involving the entire system and everyone in itº. Indeed, it has been suggested that attention to continuous improvements in process rather than a preoccupation with objective evidence of improve- ments in outcome may be the main difference between the successful Japanese model and the less successful ªWesternº one. 6There are many improvements which can be made to the ªprocessº of the anaesthesia ªsystemº which eliminate potentially dangerous situations at nominal cost.

Examples include changing the size of connectors .................................................

*This is a reprint of a paper that appeared in Anaesthesia and Intensive Care , October 1993, Volume 21, pages 502±5. .......................

Correspondence to:

Professor W B Runciman, Department of Anaesthesia and Intensive Care, Royal Adelaide Hospital, North Terrace, Adelaide, South Australia 5000; [email protected] ....................... 146 www.qualityhealthcare.com to prevent tubes being joined in dangerous con®gurations, vali- dating crisis management algorithms, re®ning check-lists, detecting and correcting de®ciencies in practice, and adding additional sequences to the tasks that should be carried out during equipment maintenance. 7 However, incident reporting cannot provide information with which to compare one individual or one institution with another; indeed, if it could it is likely that the quantity and quality of reporting would be adversely effected. At the moment, most of the ªquantitativeº systems in place cannot do this either. The variability in referral patterns and casemix will require expensive and potentially distorting ªcorrection factorsº to allow valid comparisons. What to do with those who end up in the ®fth percentile (some of whom would be there by chance) does not appear to have been addressed. It would seem more suitable to direct one's attention to the entire system, allowing a qualitative rather than a quantitative approach. Qualitative research usually starts with observations which, when categorised, may suggest the formulation of theories and hypotheses, whereas quantitative research uses measure- ments to prove or disprove existing hypotheses. The two approaches are complementary; good qualitative research may be necessary before a prospective study can be designed which has a high probability of having adequate statistical power. Let us address the relative merits of quantitative and qualita- tive research by examining the contribution of each approach to the dif®cult question of whether one can justify the use of pulse oximetry for every patient undergoing anaesthesia. The use of pulse oximetry was prospectively randomized for 20 802 patients. 89 Because no signi®cant differences were shown between the groups with and without oximeters for cer- tain ªoutcomesº, it was concluded by some observers that either pulse oximeters lacked ef®cacy or that the sample size was too small 10; however, signi®cant differences were shown for the detection of hypoxaemia, hypoventilation, endobronchial intu- bation and myocardial ischaemia, with a trend towards fewer cardiac arrests. 9Had the information published in this symposium been available at the time of designing this study, considerable time and effort could have been saved. Firstly, the ªoutcomesº chosen would not intuitively be expected to have been in¯uenced by the use of pulse oximetry, with the possible exceptions of cardiac arrest, postoperative coma and myocardial infarction, for which it was acknowledged the sample size was too small. 9Secondly, incident monitoring yielded identical con- clusions: with oximetry, signi®cantly more cases were detected with hypoxaemia, endobronchial intubation, myocardial ischae- mia and hypoventilation (when other ªdisconnectº monitors were not used) and there was a strong trend towards fewer full cardiac arrests under general anaesthesia (p=0.018). 4 Both studies have virtually identical messages for the prac- tising anaesthetist, but neither provides outcome ®gures justi- fying oximetry that would satisfy the doctrinaire quantitative biomedical scientist. However, I would argue that suf®cient evidence has been provided to justify the strong recommen- dation for all anaesthetists in Australia and New Zealand to use oximetry for every case. Problems with the airway, ventilation and endotracheal tubes which lead to hypoxaemia and hypoventilation have been responsible for at least one third of preventative deaths and cases of brain damage over the last few decades 11±13 ; oximetry indisputably detects these far earlier. 9±14 Oximetry could have prevented one third of the deaths attributable to anaesthesia in our incident monitoring study (excluding surgical deaths due to uncontrolled bleeding). 15If we accept the preoximetry ®gure of one death solely attributable to anaesthesia for each 26 000 cases as being representative of Australian practice, 16then oximetry should prevent one anaesthetic death for each 78 000 cases.

Pulse oximetry seems to have reliably picked up desaturation in well over 90% of the cases in which it was used, 14so let us assume it would prevent one death for each 100 000 cases. To provide an oximeter from before induction until discharge from the recovery ward would cost no more than $2 per patient; each life saved would thus cost about $200 000.

Taxpayer funded road improvements are generally considered pro®table up to a cost of $1.6 million per life saved 17; this translates to purchasing ªquality-adjusted life yearsº for an amount equivalent to many of the more expensive treatments in our hospitals ($30 000 to $60 000). 18Oximetry would seem to save lives at one eighth of this cost. The cost of brain dam- age, which results in greater insurance payouts than death, 13 has not been addressed. A payout of $2.3 million was awarded recently in Australia for a case in which hypoxic brain damage followed a ventilator problem. 19 When one considers the many other advantages of pulse oximetry and the fact that no value has been placed in these calculations on the peace of mind of the anaesthetist, on the quality of practice, on its utility as a teaching tool and on sequelae other than death, then a strong recommendation for the routine use of pulse oximetry in Australia and New Zealand would seem to be thoroughly justi®ed (particularly at less than $2 per case). 14 Quantitative and qualitative research are complementary; each provided the same information in the example chosen above. The quantitative study was a bold inititiative which also provided the incidence of various events and outcomes, but at a cost far greater than the qualitative study reported in this symposium. Incident monitoring is easy and cheap to implement and provides a wealth of information not only about oximetry, but the entire system. It can also provide a continuous monitor of how the system is changing in response to the implementation of strategies for improve- ment. I would argue that it represents good value for money when trying to balance cost, yield and feasibilityÐ considerations of vital importance in an era of ®nite budgets and ever-expanding possibilities. 20 21 REFERENCES1 Ustinov P . Dear Me . London: Heinemann, London, 1978: 33.

2 Bernard C . An introduction to the study of experimental medicine (translated by Green HC). New York: Dover Publications, 1985.

3 Schmerling A , Schattner P, Piterman L. Qualitative research in medical practice. Med J Aust 1993; 158:619±22.

4 Webb RK , Van der Walt JH, Runciman WB, et al . Which monitor? An analysis of 2000 incident reports. Anaesth Intens Care 1993; (in press).

5 Runciman WB , Webb RK, Klepper ID, et al . Crisis management:

validation of an algorithm by analysis of 2000 incident reports . Anaesth Intens Care 1993; 21:579±92.

6 Imai M .Kaizen: the key to Japan's competitive success . New York:

McGaw-Hill, 1986.

7 Runciman WB , Webb RK, Lee R, Holland R. System failure: an analysis of 2000 incident reports. Anaesth Intens Care 1993; 21:684±95.

8 Moller JT , Pedersen T, Rasmussen LS, et al . Randomized evaluation of pulse oximetry in 20,802 patients: I. Anesthesiology 1993; 78:436±44.

9 Moller JT , Johannessen NW, Espersen K, et al . Randomized evaluation of pulse oximetry in 20,802 patients: II. Anesthesiology 1993; 78:445±53.

10 Orkin FK , Cohen MM, Duncan PG. The quest for meaningful outcomes.

Anesthesiology 1993;78:417±22.

11 Utting JE , Gray TC, Shelley FC. Human misadventure in anaesthesia. Can Anaesth Soc J 1979;26:472±8.

12 Tiret L , Desmonts J-M, Hatton F, et al . Complications associated with anaesthesia Ð a prospective survey in France. Can Anaesth Soc J 1986; 33:336±44.

13 Caplan RA , Posner KL, Ward RJ, Cheney FW. Adverse respiratory events in anaesthesia: a closed claims analysis. Anesthesiology 1990; 72:828±33.

14 Runciman WB , Webb RJ, Barker L, Currie M. The pulse oximeter:

applications and limitations Ð an analysis of 2000 incident reports.

Anaesth Intens Care 1993; 21:543±50.

15 Morgan C , Webb RK, Cockings J, Williamson JA. Cardiac arrest: an analysis of 2000 incident reports. Anaesth Intens Care 1993; 21:626±37.

16 Holland R . Anaesthetic mortality in New South Wales. Br J Anaesth 1987;59:834±41.

17 Feedback . New Scientist 1993;1881:56.

18 Hurley S . A review of cost-effectiveness analyses. Med J Aust 1990;153:520±3.

19 Anon . The Australian . 10 August 1993, p 5 20 Baume P . On loaves and fishes. Med J Aust 1993;158:857±9.

21 Davey PJ , Leeder SR. The cost of cost of illness studies. Med J Aust 1993;158:583±4. Qualitative versus quantitative research 147 www.qualityhealthcare.com