Patient-orientated aspects of the postoperative course after hernia surgery

Abstract

Operations for inguinal hernia are one of the most common surgical procedures performed. With the development of mesh techniques, recurrence rates have improved radically and patient-orientated endpoints have evolved as important outcome measures. In recent studies, 15-50% of patients may experience some form of pain years after repair. One reason for the diverging results is the lack of a uniform assessment of postoperative pain. Pain is not defined, nor is it measured in the same way in the different studies. Moreover, postoperative complications are infrequently recorded in everyday surgical practice and many hospitals lack a continuous structured follow-up, making reliable quality assurance assessments difficult.

As quality assurance protocols are often retrospective studies rather than prospective, they will have to rely on questionnaires to be answered by the patient to get an estimate of postoperative pain and adverse events. In order to improve the performance in hernia surgery, the National Hernia Register (NHR) was started in Sweden in 1992 and today more than 90% of all inguinal and femoral hernia operations in patients 15 years and older are prospectively recorded. Information on age, gender, type of hernia as noted during the operation and type of repair as well as observed complications are recorded. Patients are entered in the register by their unique National Identification Number and can thus be traced in the register for subsequent operations regardless of the unit performing the operation as well as in other national registers. As of today more than 120 000 operations are gathered in the register. In the following papers, making the basis of this thesis, we have studied the following issues:

Paper I is a study on the discordance between the patient's and the surgeon's perception of complications. Some 206 patients having surgery for inguinal hernia were invited to a follow-up 3-6 weeks after the operation. The patient was asked to fill in a questionnaire with 12 questions concerning postoperative complications prior to the visit. The examining surgeon who had not participated in the operation and was blinded to the patient's questionnaire filled in a similar protocol. The concordance between the surgeon and the patient in assessing complications was poor and reflects their different understanding of "adverse events", the surgeon assessing technical complications and the patient the symptoms.

Paper II is based on a questionnaire study of postoperative adverse events submitted to 1643 patients recorded in the hernia register during 2 consecutive months in 2002. The response rate was 88% (1448 patients). The most common complications recorded were haematoma in 203 (14%) patients, severe pain in 168 (12%) patients, testicular pain in 120 (8%) patients and infection in 105 (7%) patients. The risk-factors for complications were age below the median of 59 years and laparoscopic repair. The National Hernia Register covered 25% of the complications recorded by the patients in the questionnaire, reflecting that a passive recording of complications, i.e. the clinic only record what comes to their knowledge, is less accurate than a structured follow-up. The study showed that a structured follow-up may improve quality control of surgery, since only a small number of the adverse events perceived by the patient come to the knowledge of the healthcare provider.

Paper III introduces the novel Inguinal Pain Questionnaire (IPQ) which is the first assessment instrument specifically designed for evaluation of pain after hernia surgery. The questionnaire consists of 18 items and is divided in a pain intensity section using a 7-step behavioural rating scale and a section for interference with daily activities with a dichotomous scale. The aim of this study is to test its validity and reliability. The validity is tested in 100 patients filling in the IPQ and Brief Pain Inventory 1 and 4 weeks after the operation for a unilateral groin hernia. Reliability and internal consistency was tested in another 100 patients filling in the IPQ 3 years after the operation on 2 occasions one month apart. Non-surgery related pain was analysed in a cohort of 2853 patients derived from the NHR, and they were sent the IPQ by regular mail 2-3 years after the operation. Non-surgery related pain was assessed by comparing pain in the groin having surgery to the side that did not. In conclusion the validity, reliability and internal consistency were acceptable. The non-surgery related pain did not exceed 5.5% for any item.

Paper IV is a study on long-term pain after hernia surgery. From the NHR 2853 patients having surgery for a unilateral groin hernia were sent the IPQ 2-3 years after the operation by regular mail with 2456 patients (86%) responding. In response to the question "worst pain past week" 758 patients (31%) reported some pain and 144 patients (6%) reported pain that interfered with daily activities. Age below median, a high level of preoperative pain, techniques involving an anterior approach and the occurrence of any postoperative complication were found to predict long-term pain.

In conclusion, quality assurance in groin hernia surgery can be facilitated by the use of local or national registers together with a structured follow-up in order to identify risk-factors and encourage a high standard of care.