in 140 patients undergoing inguinal hernia repair in the context ... age, sex, and social class, a comparison of the hernia patients ..... Normative data for adults of.
Ann R Coll Surg Engl 1997; 79: 40-45
Quality of life in patients undergoing inguina hernia repair Kate Lawrence
MSc MFPHM1
MRC Training Fellow
Douglas McWhinnie
Crispin Jenkinson DPhilI Deputy Director
MD
FRCS2
Consultant Surgeon
Angela Coulter PhD3 Director
Health Services Research Unit, Department of Public Health and Primary Care, University of Oxford 2Milton Keynes General Hospital, Milton Keynes 3King's Fund Centre, London 1
Key words: Quality of life; Hernia, inguinal; Randomised controlled trial; SF36
Inguinal hernia repair is one of the most common surgical procedures undertaken in the NHS. Despite this, no previous work has examined quality of life in this patient group. This study examines quality of life preoperatively and at 3 and 6 months postoperatively in 140 patients undergoing inguinal hernia repair in the context of a randomised controlled trial of laparoscopic versus open hernia repair. Surgery was undertaken on a day case basis, and quality of life was assessed using the Short Form 36 (SF36). In the initial phase of the study, 57% of those screened for suitability met the study inclusion criteria and were randomised. No significant differences were found between laparoscopic and open hernia repair in terms of quality of life at 3 and 6 months postoperatively. No difference was found between 3 and 6 month scores, suggesting that patients had already made a good recovery by 3 months. A significant improvement was found between preoperative and postoperative scores, with the greatest change arising on dimensions assessing pain, physical function, and role limitation owing to physical restriction. After standardising for age, sex, and social class, a comparison of the hernia patients to population norms for the SF36 was consistent with improvement from preoperative to postoperative assessment. This study has demonstrated the improvement in quality of life in patients undergoing elective inguinal hernia repair by experienced surgeons on a day case basis. It has also demonstrated the feasibility of
Correspondence to: Dr Kate Lawrence, c/o R and D Directorate, NHS Executive Anglia and Oxford, Old Road, Headington, Oxford OX3 7LF
assessing quality of life using generic measures in this patient group. Further work in this area is required. Ultimately, the priority given to elective inguinal hernia repair will depend on how the demonstrated benefits compare with those derived from other elective surgical procedures.
In recent years attempts to evaluate the outcome of different health care interventions has increased dramatically. 'Patient centred' measures of outcome, measuring quality of life after various interventions, have been developed and have been advocated for use in the evaluation of treatment efficacy (1). Inguinal hernia repair is one of the most common procedures undertaken in the NHS-64 000 elective hernia repairs are performed annually (2). Many other patients with inguinal hernia are prescribed a truss. Despite this, no previous work has explored quality of life in this patient group. More recently there has been a debate about the relative roles of laparoscopic and open approaches to repair of inguinal hernias, and their effect on quality of life postoperatively (3,4). The short form 36 (SF36) is a popular health status measure which was originally developed in North America as part of the RAND medical outcomes study (5). It is a 36-item questionnaire which measures eight dimensions of health on multi-item scales, plus a further dimension on a single item scale which measures change in health over the last year. The eight dimensions measure: physical functioning, social functioning, role limitations owing to physical problems, role limitations
Quality of life in inguinal hernia repair because of emotional problems, mental health, energy/ vitality, pain, and general health perception. Raw scores on each dimension are transformed into a 0 to 100 scale, with 100 representing the best possible health. Lower scores indicate worse health. While extensive work has established the reliability and validity of the SF36, both in American populations (6), and of an anglicised version in UK populations (7,8), further work remains to be done on its sensitivity to clinical change in a range of health states. This study explores the quality of life of patients undergoing inguinal hemia repair; using the SF36 in the context of a randomised controlled trial of laparoscopic versus open
hermia repair.
Methods Between December 1992 and March 1994 consecutive patients presenting with inguinal hernia were screened for eligibility for the study. Patients were eligible if they met local criteria for day surgery: American Society of Anaesthesia (ASA) grade I or II, age 18-70 years, simple unilateral inguinal hernia. The percentage of patients excluded after screening for suitability and the reasons for these losses were collected on a subsample of patients, until the first 125 patients had been randomised. Patients who agreed to take part in the study were randomised in the preoperative clinic to laparoscopic or open hernia repair using sealed randomisation envelopes from tables of random numbers. Surgery was undertaken by surgeons of senior registrar or consultant grade on a day case basis. Detailed description of the trial and short-term clinical outcome is reported elsewhere (3). Patients were followed up for 6 months postoperatively. The anglicised version of the SF36 was administered for self-completion by patients preoperatively and at 3 and 6 months postoperatively. Non-responders at 3 and 6 months were sent up to two postal reminders. Demographic details were recorded at baseline and patients were classified into Social Class using the Registrar General's classification (9). Analysis was undertaken using SPSS software. Patients undergoing laparoscopic and open repair were compared at 3 months and 6 months, using multivariate repeated measures analysis of covariance, taking the baseline score on the relevant dimension as the covariate. A further comparison was made between pre- and postoperative scores using paired t tests, and the mean difference in the score from preoperatively to 6 months postoperatively was calculated. Similar comparison was made by calculating the mean difference between the 3 and 6 month results. Population norms for the dimensions of the SF36 were obtained from the Oxford Regional Healthy Lifestyle Survey (10). This was a survey of a random sample of 9332 individuals of the regional population, undertaken in 1991-1992. The SF36 scores on study patients were compared with the regional population preoperatively and
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at 6 months postoperatively, after standardising for age, sex, and social class using direct standardisation.
Results On the subsample examined, 57% of those screened were randomised. Losses before randomisation were largely because patients did not meet local criteria for day surgery (79% of those excluded). Others were excluded because they had undergone previous major abdominal surgery (7%), because they wished to delay their treatment beyond the study period (3%), because they did not wish to take part in a trial (6%), or because they were unable to speak English (1%). Reason for exclusion was unrecorded in 4% of patients excluded. There were 144 patients recruited into the randomised controlled trial of laparoscopic versus open hernia repair, of whom 140 underwent surgery and were followed up for 6 months. Seventy-three patients underwent open repair, and 67 the laparoscopic procedure. At 3 months, 111 patients responded, giving a response rate of 79%, and 114 patients responded at 6 months, giving a response rate of 81%. Six-month follow-up was achieved on 57 patients undergoing open inguinal hernia repair, and 56 patients undergoing the laparoscopic procedure. The demographic details of the study population are presented in Table I. No significant difference in quality of life was demonstrated between patients undergoing laparoscopic and those undergoing open inguinal hernia repair, at 3 and 6 months postoperatively (Table II). Data for patients undergoing laparoscopic and open repair were therefore aggregated for the following analyses. For aggregated data, no significant differences were obtained between scores obtained at 3 months and those at 6 months on any dimension of the SF36 at the group level, suggesting that patients had already made a good recovery by 3 months postoperatively. Significant improvement from preoperative to 6 month postoperative scores was demonstrated on all dimensions of the SF36. This improvement was greatest in the dimensions which might be expected to be most improved by hernia repair -pain, role limitation to physical restriction and physical function (Table III). The differences were sufficiently large on these dimensions to be regarded as clinically important.
Table I. Baseline characteristics of patient groups
Median age (range) Sex Social Class I, II, IIIa IIIb, IV, V Student
Laparoscopic
Open
(n=67)
(n=73)
47 Years (20-69 Years) 66M, 1F
47 Years (20-66 Years) 70M, 3F
32 (48%) 31 (46%) 4 (6.0%)
41 (56%) 28 (38%) 4 (5.4%)
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K Lawrence et al.
Table II. Short Form 36 scores; mean (SD) Health perception Open Laparoscopic Physical mobility Open Laparoscopic Social functions Open Laparoscopic Role limitations (physical) Open Laparoscopic Role limitations (mental) Open Laparoscopic Pain Open Laparoscopic Mental health Open Laparoscopic Energy Open Laparoscopic
Baseline
3 months
6 months
Lap vs open F value (P)
80 (15) 75 (18)
83 (15) 75 (18)
84 (13) 79 (17)
2.45 (0.12)
87 (14) 80 (20)
93 (12) 91 (14)
94 (9) 94 (10)
0.52 (0.47)
93 (15) 86 (21)
95 (10) 93 (14)
94 (16) 96 (10)
0.05 (0.81)
82 (31) 66 (38)
89 (27) 85 (30)
92 (24) 95 (17)
0.06 (0.81)
90 (25) 89 (27)
92 (23) 88 (27)
94 (19) 97 (11)
0.02 (0.88)
74 (21) 67 (23)
90 (15) 83 (20)
85 (19) 91 (16)
0.32 (0.57)
80 (18) 77 (16)
84 (12) 80 (15)
85 (13) 83 (12)
1.08 (0.30)
69 (20) 65 (18)
73 (14) 71 (17)
76 (13) 72 (15)
1.14 (0.29)
Scale 0 to 100; 100 is best possible health Repeated measures ANCOVA, F value for laparoscopic versus open repair, DF 1, 113
Table III. Short Form 36 scores (mean)
Health perception Physical mobility Social functions Role limitations (physical) Role limitations (mental) Pain Mental health Energy
Baseline
3 month
6 month
Mean difference preop. to 6 months (95% CI)
77
79 92 94 87 90 87 82 72
81 94 95 94 96 88 84 74
4 (1-7) 11 (8-14) 4 (1-7) 20 (12-27) 6 (2-11) 17 (12-22) 5 (2-8) 7 (4-11)
83 90 74 90 71 79 67
Finally, preoperative and 6 month postoperative scores were standardised for age, sex, and social class. They were then compared with the scores obtained from the general population. Preoperatively, our day case hernia patients were below the population norms for the dimensions tapping pain and role limitations owing to physical restriction, and were above the norms for dimensions
tapping general health perception and role limitation because of emotional problems (Fig 1). By 6 months postoperatively our study patients were comparable to the general population norms for dimensions tapping pain and physical function, and were above them for the other dimensions (Fig. 2). This is consistent with the improvement in scores from preoperatively to 6 months postoperatively, which was demonstrated above.
Significance of mean difference P=0.005 P
