Patient-centred outcomes in clinical research: does it really matter?
‘It does not matter whether the degree of patients’ satisfaction reflects the competence of the physician or the quality of care. The important thing is that if patients are dissatisfied, health care has not achieved its goal’.1This statement, which was published 16 yr ago, reflects the (growing) importance of the technical and non-technical dimension of outcome.2 The technical aspect attempts to assess the skill and competence of professionals, and the ability of diagnostic or therapeutic procedures to accomplish what they are meant to, or, from the patients’ perspective: do they really get what they need? Patients quite rightly expect that the care they receive is methodologically sound and up-to-date, even though it may be very difficult for them to judge ‘technical’ qualities of this sort.3 The non-technical aspect relates to subjective experience, in other words, healthcare as experienced through the patient's eyes. In this context, patient satisfaction is certainly the most clinically relevant measure of outcome. 4 5 But, does that really matter at all?
In 2007, the BJA published several papers measuring patient satisfaction as a ‘secondary’ outcome.6–11 Surveys which simply assess overall satisfaction show that almost all patients are satisfied.12 13 However, we have learned that this is an over-optimistic picture, because single-item ratings lead to highly skewed distributions, with an over-estimation of satisfaction. Patients are apparently satisfied (ceiling effects) when asked only for ‘global’ measures, that is, ‘surveys which are less than excellent should give rise to concern’.14 Moreover, knowing that more than 95% of all patients are satisfied makes it almost impossible to set improvement measures.
So, what is the right way to measure patient satisfaction? To answer that question, we must first of all understand what is meant by the term ‘satisfaction’. Many include patient expectations as the basic concept of satisfaction,15 16 and therefore define satisfaction as the degree of congruence between expectation and accomplishment.17 18 This means that we must know what patients expect before we ask about satisfaction with the care they have received.
Research ethic committees, editors, reviewers, and last but not least, readers share a common problem: they have to assess whether a special instrument—normally a self-report questionnaire—is actually able to measure what it claims, in our case, patient satisfaction. The development process of health measurement scales is rather complex and must follow a rigorous step-by-step approach.19–21 Basically, it should include at least elements of content validity, construct validity, and reliability. Content validity implies that the instrument must contain all relevant factors important to the trait under study. To assure high content validity, a literature search, expert's and patient's view should therefore be included. Construct validity assesses whether the instrument really measures what we think it should measure. A major point in this context is whether the aspects being assessed are ‘translated’ in a comprehensive way into questions. Another method to check for construct validity is the inclusion of already validated scales in the test questionnaire. The relationship between similar constructs in the new questionnaire with gold standard scales then becomes a measure of the external or concurrent validity. The basic concept of reliability is simple. It is a way to reflect the amount of error which is inherent in any measurement. In principle, there are two approaches to evaluate reliability; stability refers to the reproducibility of an instrument, in terms of administration by different scorers or by the same scorer on different occasions or time-intervals (e.g. test–retest reliability), scale reliability evaluates the extent that the items incorporated into a scale actually measure the underlying construct. The correlation between items measuring the same construct is usually described by internal consistency. A classic approach to measure internal consistency of a scale is to determine the Cronbach 
reliability coefficient. A coefficient of 0.7, for example, tells us that 70% of the variance in scores is due to true variation and 30% is due to measurement error (i.e. inaccuracy in measurement). In general, values greater than 0.70 are considered acceptable.
As mentioned above, single-item ratings are unqualified to measure patient perceptions. Patient satisfaction (with anaesthesia care) should therefore be measured multi-dimensionally using a multi-item technique for each dimension.22–24
Patient satisfaction surveys in anaesthesia which are performed with psychometrically developed questionnaires have shown that ‘information’ is by far the most important dimension to assure high patient satisfaction in the perioperative period.24 As most ‘information’ is communicated in the preoperative phase, the measurement of the performance of a preoperative assessment clinic makes a major contribution to a total satisfaction score.
In the November issue 2007 of the British Journal of Anaesthesia, Edward and colleagues25 described the development of an instrument to measure patient experience of a preoperative assessment clinic. Their study provides evidence for a psychometric development process and the whole questionnaire is shown in the appendix. Although the primary goal was to deliver a ‘recipe’ of how to develop a valid and reliable instrument, the strength of the paper could have been improved by presenting the detailed results. Roughly speaking, there is a wonderful cake, but you do not know how it tastes. Nevertheless, we have to appreciate Edward and colleagues’ work, and we would recommend using their cost-free recipe to assess the experience of your patients.
A further problem with surveys of patient satisfaction is the use of surrogate endpoints.26 This means incidents (e.g. postoperative pain, nausea, and vomiting) or activities (e.g. pain management) are used instead of the true outcome measure (e.g. patient satisfaction). The main problem is the wrong and, in most cases, unproven assumption of a positive relationship between the surrogate endpoint and the true outcome.27 Researchers often take it for granted that patients with postoperative pain are automatically dissatisfied with pain management or, worse, that postoperative pain is directly linked to patient dissatisfaction. For example, Svensson and colleagues28 studied the influence of expectations and pain experiences on patient satisfaction with pain management. Even though 91% of patients expected moderate to severe pain and 76% reported such pain, only 8% were dissatisfied. Although pain management contributes to global satisfaction, its influence is far less than, for instance, information or continuity of care.
Patient satisfaction is beyond doubt an important non-technical outcome measure. However, statements about patient satisfaction should be based only on results from surveys with valid and reliable instruments. Single-item ratings do not give a true indication of care. The use of surrogate endpoints instead of valid outcome measures must be regarded very cautiously until a definite correlation has been scientifically established.
Department of Anaesthesia
Spitalregion Rheintal Werdenberg Sarganserland
Spitalstrasse 5
8880 Walenstadt
Switzerland
Empirical Consulting (GEB mbH)
Hauptstrasse 67.1
79211 Denzlingen
Germany
Department of Anaesthesia and Intensive Care
Landeskrankenhaus
6800 Feldkirch
Austria
Research Ethics Committee
Kanton St Gallen
Rorschacherstrasse 95
9007 St Gallen
Switzerland
* E-mail: thomas.heidegger{at}srrws.ch
References
1 Vuori H. Patient satisfaction—does it matter? Qual Assur Health Care (1991) 3:183–9.[Medline]
2 Gerteis M, Edgman-Levitan S, Daley J, Delbanco TL. Through the Patient's Eyes (1993) San Francisco: Jossey-Bass Publishers. xi–xix.
3 Allshouse KD. Treating patients as individuals. In: Through the Patient's Eyes—Gerteis M, Edgman-Levitan S, Daley J, Delbanco TL, eds. (1993) San Francisco: Jossey-Bass Publishers. 19–44.
4 Hopkins PM. A shame about the patient? Br J Anaesth (2000) 84:1–2.
5 Cleary PD, McNeil BJ. Patient satisfaction as an indicator of quality of care. Inquiry (1988) 25:25–36.[Web of Science][Medline]
6 Aubrun F, Amour J, Rosenthal D, Coriat P, Riou B. Effects of a loading dose of morphine before i.v. morphine titration for postoperative pain relief: a randomized, double-blind, placebo-control study. Br J Anaesth (2007) 98:124–30.
7 Michelet P, Guervilly C, Helaine A, et al. Adding ketamine to morphine for patient-controlled analgesia after thoracic surgery: influence on morphine consumption, respiratory function, and nocturnal desaturation. Br J Anaesth (2007) 99:396–403.
8 Jokela R, Ahonen J, Valjus M, Seppala T, Korttila K. Premedication with controlled-release oxycodone does not improve management of postoperative pain after day-case gynaecological laparoscopic surgery. Br J Anaesth (2007) 98:255–60.
9 Nightingale JJ, Knight MV, Higgins B, Dean T. Randomized, double-blind comparison of patient-controlled epidural infusion vs nurse-administered epidural infusion for postoperative analgesia in patients undergoing colonic resection. Br J Anaesth (2007) 98:380–4.
10 Tauzin-Fin P, Sesay Svartz L, Krol-Houdek MC, Maurette P. Sublingual oxybutynin reduces postoperative pain related to indwelling bladder catheter after radical retropubic prostatectomy. Br J Anaesth (2007) 99:572–5.
11 van Zundert AA, Stultiens G, Jakimowicz JJ, et al. Laparoscopic cholecystectomy under segmental thoracic spinal anaesthesia: a feasibility study. Br J Anaesth (2007) 98:682–6.
12 Fung D, Cohen MM. Measuring patient satisfaction with anaesthesia care: a review of current methodology. Anesth Analg (1998) 87:1089–98.
13 Jenkinson C, Coulter A, Bruster S, Richards N, Chandola T. Patients’ experiences and satisfaction with health care: results of a questionnaire study of specific aspects of care. Qual Saf Health Care (2002) 11:335–9.
14 Carey RG, Posavec EJ. Using patient information to identify areas for service improvement. Health Care Manage Rev (1982) 7:43–8.[Medline]
15 Thompson AG, Sunol R. Expectations as determinants of patient satisfaction: concepts, theory and evidence. Int J Qual Health Care (1995) 7:127–41.
16 Wu CL, Naqibuddin M, Fleisher LA. Measurement of patient satisfaction as an outcome of regional anaesthesia and analgesia: a systematic review. Reg Anesth Pain Med (2001) 26:196–208.[CrossRef][Web of Science][Medline]
17 LaMonica E, Oberst M, Madea A, et al. Development of a patient satisfaction scale. Res Nurs Health (1986) 9:43–50.[Web of Science][Medline]
18 Pascoe GC. Patient satisfaction in primary health care: a literature review and analysis. Eval Program Plann (1983) 6:185–210.[CrossRef][Medline]
19 Streiner DL, Norman GR. Health Measurement Scales. A Practical Guide to their Development and Use (1995) 2nd Edn. Oxford: Oxford University Press.
20 De Vellis RF. Scale Development. Theory and Applications (1991) 1st Edn. London: Sage Publications.
21 Sitzia J. How valid and reliable are patient satisfaction data? An analysis of 195 studies. Int J Qual Health Care (1999) 11:319–28.
22 Auquier P, Pernoud N, Bruder N, et al. Development and validation of a perioperative satisfaction questionnaire. Anesthesiology (2005) 102:1116–23.[CrossRef][Web of Science][Medline]
23 Heidegger T, Husemann Y, Nuebling M, et al. Patient satisfaction with anaesthesia care: development of a psychometric questionnaire and benchmarking among six hospitals in Switzerland and Austria. Br J Anaesth (2002) 89:863–72.
24 Heidegger T, Saal D, Nuebling M. Patient satisfaction with anaesthesia care: what is patient satisfaction, how should it be measured, and what is the evidence for assuring high patient satisfaction? Best Pract Res Clin Anaesthesiol (2006) 20:331–46.[CrossRef][Medline]
25 Edward GM, Lemaire LC, Preckel B, et al. The patient experiences with the preoperative assessment clinic (PEPAC): validation of an instrument to measure patient experiences. Br J Anaesth (2007) 99:666–72.
26 Lauritsen J, Møller AM. Publications in anesthesia journals: quality and clinical relevance. Anesth Analg (2004) 99:1486–91.
27 Wu CL, Fleisher LA. Outcomes in perioperative medicine and anesthesiology. Into the next millennium. Anesthesiol Clin North America (2000) 18:633–45.[CrossRef][Medline]
28 Svensson I, Sjostrom B, Haljamae H. Influence of expectations and actual pain experiences on satisfaction with postoperative pain management. Eur J Pain (2001) 5:125–33.[Web of Science][Medline]
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  M. A. A. Caljouw, M. van Beuzekom, and F. Boer Patient's satisfaction with perioperative care: development, validation, and application of a questionnaire Br. J. Anaesth., May 1, 2008; 100(5): 637 - 644. [Abstract] [Full Text] [PDF]
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