Carpal tunnel syndrome is the most common compression neuropathy of the upper extremity, with an incidence of approximately 3.5 cases per 1000 person-years.1 Surgical release of the entrapped median nerve under the carpal ligament is considered the most effective long-term method of treatment.2
Many studies have focused on identifying predictors of success and failure after surgical treatment of carpal tunnel syndrome.3–5 Success after surgery is often described in terms of outcomes directly related to the procedure itself (e.g., lack of complications, symptom relief, and regaining functionality of the hand). These parameters are part of an overall quality rating and can be assessed by the health care providers but can also be reported by patients themselves in patient-reported outcome measures. The latter provides a helpful tool, not only for surgical outcome but also for assessing disease severity and disease progression in both a clinical and a research setting.6 In the field of hand surgery, commonly used patient-reported outcome measure tools include the Michigan Hand Outcomes Questionnaire7; the Disabilities of the Arm, Shoulder and Hand questionnaire8; and the Boston Carpal Tunnel Assessment Questionnaire,9 with the latter specifically designed for patients with carpal tunnel syndrome.
Increasingly more attention has been directed not just toward measuring success after treatment, but also on the incorporation of the evaluation of the health care process, to provide a more complete measure of success.10 Patient-reported experience measures are tools that help gain insight into the health care process from the patient’s perspective11 and can act as a robust, distinctive indicator of health quality.12 So far, patient-reported experience measures have not often been used to investigate the effect of health care experiences on clinical outcome in the field of hand surgery, but they have been used as possible predictors of success for several elective operations, including knee and hip replacements and hernia repairs.10,13,14 Also, a recently published study describes using patient-reported experience measures to distill points of attention to improve the patient’s experience of elective surgery. They found, for example, that patients treated later in the day were significantly less likely to report a positive experience. Knowing this, they could evaluate the effect of targeted improvements for this patient group (decrease waiting time and fasting, establish more realistic expectations) and reported a 30 percent increase in positive experiences.15 This study illustrates how patient-reported experience measures can be used in a study design for both identification of problems and assessment of the effect. The question remains, however, of whether changes based on patient-reported experience measure scores improve only satisfaction rates or also clinical outcomes. Because carpal tunnel release surgery is among the most commonly performed orthopedic hand treatments, with an annual case load of approximately 400,000 to 500,000 in the United States alone,16 it provides an interesting patient population for further investigation.
To assess the possible association between patient-reported experience measures and patient-reported outcome measures in patients with carpal tunnel syndrome, patients who underwent a carpal tunnel release operations were selected from a large database with routinely collected outcome measures. Using a preoperative patient-reported outcome measure instrument and both a postoperative patient-reported experience measure and a patient-reported outcome measure instrument, the association between a higher patient-reported experience measure score and the difference in clinical outcome will be reported, hypothesizing a positive effect.
PATIENTS AND METHODS
This is a cohort study using prospectively acquired data. As part of a routine outcome measurement, all patients who underwent carpal tunnel release as part of their carpal tunnel syndrome treatment were asked to participate. Written informed consent was obtained for all participants, in compliance with the Declaration of Helsinki.17 Patients were included between November of 2011 and September of 2017, and data were collected in a consortium of 16 national hand surgery practice sites. Study data were collected and managed using GemsTracker (i.e., GEneric Medical Survey Tracker) electronic data capture tools.18 GemsTracker is a secure Web-based application for distribution of questionnaires and forms during medical research and quality registrations. Data extraction was performed in December of 2017. Carpal tunnel syndrome diagnosis was made based on symptoms of numbness or tingling in the distribution area of the median nerve and nocturnal aggravation in combination with clinical examination including Phalen and Tinel tests. To ensure complete data, a selection was made based on availability of patient-reported outcome measures at baseline and patient-reported experience measure and patient-reported outcome measures postoperatively. If patients were included twice (e.g., because of repeated surgery or bilateral carpal tunnel syndrome), only the chronologic first data set was used. Patients were invited to complete an e-mailed patient-reported outcome measure questionnaire before surgery and both a patient-reported outcome measure and a patient-reported experience measure questionnaire 3 months after surgery. Two reminders were e-mailed to nonresponders. In addition, data on age, sex, body mass index, alcohol, smoking, dominance, occupational intensity, and duration of symptoms were collected.
A Dutch version of the Boston Carpal Tunnel Assessment Questionnaire9 was used as a patient-reported outcome measure. This questionnaire consists of two parts: a symptom severity scale and a functional status scale. The symptom severity scale indicates how severe the symptoms are, as experienced by the patient, and the functional status scale indicates how much interference the patient experiences with daily activities. Each score can range from 1 (no symptoms) to 5 (most severe), with the symptom severity scale consisting of 11 and the functional status scale consisting of eight questions.
The patient-reported experience measure consisted of a questionnaire commonly used in private practice clinics throughout The Netherlands. Questions target the patient’s experiences with associated health staff and the medical facility at various time points during their treatment. By means of an exploratory factor analysis, as described in a recent study,19 six subscales were identified to assess experiences across different domains: physician communication and competence, perioperative care, postoperative care, general information, treatment information, and quality of facilities (see Appendix). For each item, patients were asked to give a score in line with the Dutch Academic grading system, where a value of 1 represents a very poor result, a value 10 indicates an excellent result, and a value of 6 indicates the lowest passing grade. This method of outcome was chosen because of the high degree of familiarity of the Dutch population with this particular grading system. If a question did not apply to a patient (e.g., if they did not use the website), there was a possibility to answer accordingly. For questions concerning follow-up care, it is relevant to know that in the included hand clinics, it is standard protocol for all patients to be offered follow-up by a hand therapist. Internal consistency in our sample, estimated using Cronbach α, was as follows: physician communication and competence, 0.96; perioperative care, 0.52; postoperative care, 0.91; general information, 0.92; treatment information, 0.88; and quality of facilities, 0.87.
All analyses were performed using R statistical computing.20 Patient-reported experience measure subscale scores were calculated by averaging the scores given to the corresponding questions per subscale. Patient-reported outcome measure results were also calculated by averaging the separate scores for both subscales, and the difference between the preoperative and postoperative questionnaires was used as the dependent variable. Significance testing for preoperative and postoperative patient-reported outcome measure scores was performed using a paired t test for normally distributed data and a Wilcoxon signed rank test for nonnormally distributed data. Distribution of the data was evaluated visually using histograms and QQ norm plots. An effect size was calculated to compare the patient-reported outcome measure scores before and after surgery by using the Cohen d for a matched sample comparison (dividing the t statistic by the square root of n).21 To assess the association between increased patient-reported experience measure scores and patient-reported outcome measure change scores, linear regression analyses were used. In these models, the beta coefficients represent the change in overall symptom severity scale/functional status scale score associated with 1 absolute point increase in patient-reported experience measure subscale. Multivariable regression models were used to adjust for potential confounding of various patient and disease characteristics, including age, sex, body mass index, smoking, alcohol, occupational intensity, surgery on the dominant hand, first time surgery, and duration of disease. Approximately 18 percent of patients had missing data on body mass index, alcohol, and smoking; thus, the adjusted model was performed on a sample size of 1311. An additional comparative analysis on demographics was performed to compare the final data set to those who missed either their follow-up patient-reported outcome measure or the patient-reported experience measures. Significant differences were found in age and the number of positive responders with regard to smoking and alcohol use, but these were attributed to the large size of the sample and regarded as not clinically relevant. All subsequent analyses were performed with the complete data set. To determine to what extent the variation in treatment outcome between patients could be explained by the experience with health care delivery, all six patient-reported experience measure subscales were introduced simultaneously in the same model as independent variables. Significance was set at an alpha lower than 0.05.
Complete data sets on a total of 1607 patients were included (Fig. 1). Table 1 lists the patient demographics. The sample included more women than men (71.6 percent), and the majority of cases involved the dominant hand (58.9 percent). Duration of symptoms varied, with a median value of 12 months (interquartile range, 30 months).
Absolute scores for both the patient-reported outcome measures and the patient-reported experience measures are shown in Tables 2 and 3. Both scales of the Boston Carpal Tunnel Assessment Questionnaire were normally distributed at baseline, with a normally distributed difference in means before and after surgery. The average patient-reported outcome measure scores decreased, with 1.13 for the symptom severity scale and 0.72 for the functional status scale, showing a significant decrease 3 months after carpal tunnel release (p < 0.001) and effect sizes of 1.50 and 0.94, respectively. Patient-reported experience measure scores indicated a generally positive experience, ranging between median values of 8 and 8.5 over the six different subscales. Different subscales showed between 0 and 18 percent missing data, the main reason for which was that some of the specific topics (e.g., information provided by means of a website/brochure) in the patient-reported experience measures were not applicable to specific patients.
The unadjusted regression analyses for both subscales of the patient-reported outcome measures showed significant (p < 0.001) negative associations with all individual patient-reported experience measure subscales (Table 4), indicating that better patient-reported experience measure are associated with better (i.e., lower) patient-reported outcome measure (Boston Carpal Tunnel Assessment Questionnaire) change scores. Values ranged from −0.08 to −0.17 in patient-reported outcome measure point difference as a result of a one-point increase on the patient-reported experience measure subscales. The strongest associations were found in the “physician communication and competence,” “postoperative care,” and “treatment information” subscales. Explained variance in patient-reported outcome measure score, considering all patient-reported experience measure subscales, was 5.5 percent for the symptom severity scale and 5.3 percent for the functional status scale. In the adjusted, multivariable regression, patient characteristics added to the explained variance to a total of 8.9 percent for the symptom severity scale and 9.8 percent for the functional status scale.
In this large data set involving carpal tunnel syndrome patients who underwent a surgical release procedure, we found that better health care experiences are associated with better clinical outcome in self-reported postsurgical questionnaires. The largest effects were found in the experiences with physician communication and competence, postoperative care, and treatment information. Altogether, the patient-reported experience measures constituted more than 5 percent of the explained variance in patient-reported outcome measure score change, where patient characteristics explained an additional 3.5 to 4.5 percent.
Both our effect size and the patient-reported experience measure/patient-reported outcome measure association are in line with what has been described before.22 A study by Black et al. showed an overall weak association on both the Oxford Hip Score and the Oxford Knee Score after hip or knee replacement as a response to change in overall patient-reported experience measure scores.10 More specifically, their greatest effect was also found in the doctor’s trust and communication section, but as in our study, data did not allow for any conclusions on (the direction of) causality.
The influence of patient-physician communication has been described in other articles as well: on satisfaction, good communicative skills have a stronger effect than, for example, time spent with the patient, as was found in patients from hand and orthopedic surgeon populations.23–26 Satisfaction is thus linked more to perceived quality of the conversation than the quantity. In addition, a recent meta-analysis has found that patients report more beneficial health behavior, fewer symptoms, and higher quality-of-life scores when they reported more trust in their health care professional.27 Improving physician empathy with, for example, communication training has been shown to lower depression,28 reduce pain levels,29 and improve medication adherence.30 Another meta-analysis identified 13 articles describing randomized controlled trials that empirically tested methods of improving the patient-clinician relationship, focusing on trust and empathy. After improving the patient-clinician relationship, a small but significant effect was found on outcomes in a variety of abnormalities,31 indicating the possible direction and translatability of studies performed concerning this topic.
Another patient-reported experience measure category that stood out in our results was treatment information. The relatively higher scores in this subcategory indicate that taking away uncertainties about the surgical process and providing information on the recovery period will help in achieving better patient-reported outcome measures. A previous survey study showed that it is mostly the surgical outcome that determines the success in the eyes of the patient; thus, achieving a realistic expectation could improve clinical outcome.32
The main strengths of the present study are the size of the data set, the robust implementation in standardized clinical care, and the emphasis on patient-reported data. The internal consistency was excellent for all subcategories except perioperative care. Because the patient-reported experience measure questions were selected on applicability from a larger set of questions, only two questions remained in this category, which in part explains the lower consistency. This study focused on using patient-reported outcome measures as the main outcome parameter after surgery rather than the perhaps more classic objective measurements such as grip strength or the need for a second operation. Because patients and clinicians do not appear to have a universal agreement as to what determines success after surgery,33,34 objective measures might not adequately reflect success of a surgical procedure. As mentioned before, modern medicine is shifting more toward a personalized approach with an emphasis on patient feedback that includes having a better understanding of patient experiences and how possible effects on clinical outcome fits in that model.
Intrinsic to the design of the acquisition method used to create the database, there are limitations to the generalizability of our results. The explained variance and increase in patient-reported outcome measure scores in this study were tested by means of a multiple regression, meaning that, although an effect was found, causality is not proven. It might be that our findings indicate that better postoperative outcomes lead to a more positive memory of health care experiences. Second, potential confounders such as psychological state or recollection bias of the patient were not taken into account in this analysis. Future studies should address this using more extensive measurement tools acquired at multiple time points, including a presurgical evaluation. Also, information was gathered based on patients who visited a specialized care center outside of an academic/regular hospital setting, implying that there could be a selection bias, with a relatively low occurrence of nontypical carpal tunnel syndrome presentations. The structural validity of the patient-reported experience measure questionnaire used in this study was determined using a factor analysis, but it is important to note that no test-retest reliability, responsiveness, or cross-cultural validation was performed. In addition, in the current sample, detailed information on other (relevant) musculoskeletal diseases, medical history, and occupational intensity was not available. In standard practice, occurrences of corticosteroid injections and other conservative therapies, which might have played a role in our clinical outcome, are very low because of reserved use as described in a guideline published by the Dutch Association of Neurology.35 Nonetheless, any interference of other hand-related abnormalities on the Boston Carpal Tunnel Assessment Questionnaire scores needs be taken into consideration. This applies mostly to the functional scale, as the symptom severity scale uses questions specifically designed for the clinical carpal tunnel syndrome presentation.
This study demonstrates that experiences as reported by carpal tunnel release patients on health care delivery are associated with their treatment outcomes. Although it is important in its own right to assess and improve health care experiences of these and others patients, our study provides an additional reason to further explore interventions aimed at improving the context in which health care is provided. These future studies would also support uncovering the presence of causality and potential directionality of the relationship between patient-reported experience measures and patient-reported outcome measures.
The authors would like to thank all patients who filled out questionnaires as part of their clinical care and have agreed to let their data be used anonymously for the present study. In addition, they would like to acknowledge the members of the Hand-Wrist Study Group, caregivers and personnel of Xpert Clinic, Handtherapie Nederland, and Equipe Zorgbedrijven for assisting in the routine outcome measurements that are the basis for this article.
1. Nordstrom DL, DeStefano F, Vierkant RA, Layde PM. Incidence of diagnosed carpal tunnel syndrome in a general population. Epidemiology 1998;9:342–345.
2. Huisstede BM, van den Brink J, Randsdorp MS, Geelen SJ, Koes BW. Effectiveness of surgical and postsurgical interventions for carpal tunnel syndrome: A systematic review. Arch Phys Med Rehabil. 2018;99:1660–1680.
3. Jerosch-Herold C, Shepstone L, Wilson EC, Dyer T, Blake J. Clinical course, costs and predictive factors for response to treatment in carpal tunnel syndrome: The PALMS study protocol. BMC Musculoskelet Disord. 2014;15:35.
4. Watchmaker JD, Watchmaker GP. Independent variables affecting outcome of carpal tunnel release surgery. Hand (N Y) 2018;13:285–291.
5. Turner A, Kimble F, Gulyás K, Ball J. Can the outcome of open carpal tunnel release be predicted? A review of the literature. ANZ J Surg. 2010;80:50–54.
7. Chung KC, Hamill JB, Walters MR, Hayward RA. The Michigan Hand Outcomes Questionnaire (MHQ): Assess ment of responsiveness to clinical change. Ann Plast Surg. 1999;42:619–622.
8. Hudak PL, Amadio PC, Bombardier C. Development of an upper extremity outcome measure: The DASH (disabilities of the arm, shoulder and hand) [corrected]. The Upper Extremity Collaborative Group (UECG). Am J Ind Med. 1996;29:602–608.
9. Levine DW, Simmons BP, Koris MJ, et al. A self-administered questionnaire for the assessment of severity of symptoms and functional status in carpal tunnel syndrome. J Bone Joint Surg Am. 1993;75:1585–1592.
10. Black N, Varaganum M, Hutchings A. Relationship between patient reported experience (PREMs) and patient reported outcomes (PROMs) in elective surgery. BMJ Qual Saf. 2014;23:534–542.
12. Manary MP, Boulding W, Staelin R, Glickman SW. The patient experience and health outcomes. N Engl J Med. 2013;368:201–203.
13. Baker PN, Deehan DJ, Lees D, et al. The effect of surgical factors on early patient-reported outcome measures (PROMS) following total knee replacement. J Bone Joint Surg Br. 2012;94:1058–1066.
14. Clement ND, Macdonald D, Burnett R, Simpson AHRW, Howie CR. A patient’s perception of their hospital stay influences the functional outcome and satisfaction of total knee arthroplasty. Arch Orthop Trauma Surg. 2017;137:693–700.
15. Fregene T, Wintle S, Venkat Raman V, Edmond H, Rizvi S. Making the experience of elective surgery better. BMJ Open Qual. 2017;6:e000079.
16. Palmer DH, Hanrahan LP. Social and economic costs of carpal tunnel surgery. Instr Course Lect. 1995;44:167–172.
17. World Medical Association. World Medical Association Dec laration of Helsinki: Ethical principles for medical research involving human subjects. JAMA 2013;310:2191–2194.
18. GemsTracker. Erasmus MC and Equipe Zorgbedrijven, version 1.8.2. Available at: https://gemstracker.org
. Accessed April 10, 2018.
19. Poelstra R, Selles RW, Slijper HP, et al. Better patients’ treatment experiences are associated with better postoperative results in Dupuytren’s disease. J Hand Surg Eur Vol. 2018;43:848–854.
21. Rosenthal R. Meta-Analytic Procedures for Social Research. 1991.Newbury Park, Calif: Sage.
22. Leite JC, Jerosch-Herold C, Song F. A systematic review of the psychometric properties of the Boston Carpal Tunnel Questionnaire. BMC Musculoskelet Disord. 2006;7:78.
23. Teunis T, Thornton ER, Jayakumar P, Ring D. Time seeing a hand surgeon is not associated with patient satisfaction. Clin Orthop Relat Res. 2015;473:2362–2368.
24. Kedia R, Dargan C, Hassan O, Dasa V. Pain, functional scores, and radiographic severity of illness influence the perception of time spent with the physician by patients presenting for initial evaluation of knee osteoarthritis. Ochsner J. 2016;16:457–463.
25. Parrish RC II, Menendez ME, Mudgal CS, Jupiter JB, Chen NC, Ring D. Patient satisfaction and its relation to perceived visit duration with a hand surgeon. J Hand Surg Am. 2016;41:257–262.e1.
26. Menendez ME, Chen NC, Mudgal CS, Jupiter JB, Ring D. Physician empathy as a driver of hand surgery patient satisfaction. J Hand Surg Am. 2015;40:1860–1865.e2.
27. Birkhäuer J, Gaab J, Kossowsky J, et al. Trust in the health care professional and health outcome: A meta-analysis. PLoS One 2017;12:e0170988.
28. Fujimori M, Shirai Y, Asai M, Kubota K, Katsumata N, Uchitomi Y. Effect of communication skills training program for oncologists based on patient preferences for communication when receiving bad news: A randomized controlled trial. J Clin Oncol. 2014;32:2166–2172.
29. Chassany O, Boureau F, Liard F, et al. Effects of training on general practitioners’ management of pain in osteoarthritis: A randomized multicenter study. J Rheumatol. 2006;33:1827–1834.
30. Kim SS, Kaplowitz S, Johnston MV. The effects of physician empathy on patient satisfaction and compliance. Eval Health Prof. 2004;27:237–251.
31. Kelley JM, Kraft-Todd G, Schapira L, Kossowsky J, Riess H. The influence of the patient-clinician relationship on healthcare outcomes: A systematic review and meta-analysis of randomized controlled trials. PLoS One 2014;9:e94207.
32. Khu KJ, Bernstein M, Midha R. Patients’ perceptions of carpal tunnel and ulnar nerve decompression surgery. Can J Neurol Sci. 2011;38:268–273.
33. Janse AJ, Gemke RJ, Uiterwaal CS, van der Tweel I, Kimpen JL, Sinnema G. Quality of life: Patients and doctors don’t always agree. A meta-analysis. J Clin Epidemiol. 2004;57:653–661.
34. Amadio PC, Wood MB, Cooney WP, Bogard SD. Staged flexor tendon reconstruction in the fingers and hand. J Hand Surg Am. 1988;13:559–562.
Appendix: PREM Questionnaire Translated from Dutch to English*
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