- Email: [email protected]
Patient satisfaction and quality of life status after 2 treatment modalities: Invisalign and conventional fixed appliances
ORIGINAL ARTICLE
Patient satisfaction and quality of life status after 2 treatment modalities: Invisalign and conventional fixed appliances Carlos Flores-Mir, Jeremy Brandelli, and Camila Pacheco-Pereira Edmonton, Alberta, Canada Introduction: Our objectives were to assess patient satisfaction and quality of life among adults via 2 validated comprehensive questionnaires and to compare patient satisfaction and status in oral health-related quality of life immediately after orthodontic treatment in patients treated with Invisalign (Align Technology, San Jose, Calif) and those who received standard bracket-based treatment. Methods: Adult patients (n 5 145) treated with bracketbased or Invisalign therapy were recruited from several private practices and a university clinic. The survey comprised a combination of the Dental Impacts on Daily Living index and the Patient Satisfaction Questionnaire. This 94-question assessment focused on various dimensions of satisfaction and quality of life. Multivariate analysis of variance and the bootstrap test were applied. A reliability analysis was used to assess responses at a 6-month follow-up for a small sample of patients. Results: Finally, 122 patients were assessed. The multivariate analysis of variance analysis showed that the eating and chewing dimension was significantly different between the 2 groups (Invisalign, 49%; bracket based, 24%; P 5 0.047). No significant difference in any other satisfaction factors (all, P . 0.05) was identified. The follow-up assessment was only possible in a small sample of the bracket group; it showed adequate reliability values on the categories of oral comfort (intraclass correlation coefficient [ICC], 0.71), general performance (ICC, 0.755), situational (ICC, 0.80), and doctor-patient relationship (ICC, 0.75). Conclusions: Of the patients surveyed to assess their satisfaction and oral health-related quality of life immediately after completion of their orthodontic treatment, both the bracket-based and Invisalign treated patients had statistically similar satisfaction outcomes across all dimensions analyzed, except for eating and chewing: the Invisalign group reported more satisfaction. Patient satisfaction remained relatively similar 6 months later for the bracket-type treatment. (Am J Orthod Dentofacial Orthop 2018;154:639-44)
P
atient satisfaction, as related to oral health care, can be defined as a patient's personal evaluation of the services provided to him or her.1 It can be used as 1 measure of the overall quality of health care; therefore, it has resulted in increased interest in quantifying and qualifying patient satisfaction with dental
From the School of Dentistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada All authors completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. They reported that the 2015 North America Align Research Award Program (number RES0026582) supported this work. The funding agency did not influence the interpretation of the surveys. Dr. Pacheco-Pereira reported personal fees from Align Technology Inc, during the conduct of the study. Address correspondence to: Camila Pacheco-Pereira, School of Dentistry, Faculty of Medicine and Dentistry, 5-533 Edmonton Clinic Health Academy, 11405-87 Avenue NW, University of Alberta, Edmonton, AB, Canada T6G 1C9; e-mail, [email protected]. Submitted, October 2017; revised and accepted, January 2018. 0889-5406/$36.00 Ó 2018 by the American Association of Orthodontists. All rights reserved. https://doi.org/10.1016/j.ajodo.2018.01.013
treatment.2 Nonetheless, due to different motivations and expectations for seeking oral health care, professional assessments of treatment outcomes may differ from those of their patients.3,4 This is also true for orthodontic treatment, where motivation to seek treatment includes esthetics, improved dental function, and psychological benefit; these motivations occur at different degrees in different patients, and younger patients may even lack motivation for treatment since they are brought in by their parents.4,5 Previous studies examining patient satisfaction with fixed appliances have suggested that some patients may experience pain and discomfort immediately after orthodontic appliances are bonded as well as sometimes after regular visits. This was negatively correlated with patient satisfaction.6 However, at the end, the vast majority of patients were satisfied with the outcomes of their orthodontic treatment.7,8 Furthermore, although temporary negative effects on function and social and 639
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emotional well-being are expected as side effects of standard bracket-based treatment, these effects were significantly less than what patients expected before starting treatment.9 Clear aligners were introduced to provide orthodontic treatment with a more esthetic, removable appliance. However, a previous study showed that 50% of patients undergoing Invisalign (Align Technology, San Jose, Calif) treatment were self-conscious about their appearance during treatment.10 Most patients reported satisfaction with the results of their orthodontic treatment and improvement in self-confidence after treatment.10 Furthermore, oral health-related quality of life (OHRQoL) was only minimally affected during treatment.11 There are many factors to consider when choosing between clear aligners and conventional bracket-based treatment. The ability to remove the clear aligners may make it easier for patients to maintain good oral hygiene,11 but studies have shown conflicting results. One study suggested poorer gingival health in the bracket-based group compared with the Invisalign group but equal plaque accumulation between the 2 groups in a sample of adults and children.12 Another study showed that subjects with the fixed appliance modality retained more plaque, but the gingival health between the 2 treatments was nearly identical.13 Patient satisfaction was reported to be higher in the Invisalign group, with these patients reporting more willingness to redo the same treatment, fewer changes in eating habits, and less decrease in overall well-being during treatment.12 Few studies have combined the effects of different treatment modalities on adult patient satisfaction and quality of life (QoL). Most previous studies assessing satisfaction applied nonvalidated questionnaires; some used only 1 question or a few questions addressing satisfaction as an overall statement. These tools could be considered susceptible to subjectivity and likely compromise the reliability or internal validity of the questions. Therefore, in this study, we aimed to assess adult patients' satisfaction and OHRQoL status immediately after orthodontic treatment via 2 validated, wide-ranging questionnaires and to compare patient satisfaction and changes in OHRQoL immediately after orthodontic treatment on patients who had Invisalign or bracket-type treatment. MATERIAL AND METHODS
Approval from the Research Ethics Board at the University of Alberta in Canada was granted for the protocol and informed consent process of this study (Pro00056779). An observational cross-sectional study was planned to compare the factors related to treatment
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satisfaction and OHRQoL status in adult orthodontic patients treated with either the Invisalign (Align Technology, San Jose, Calif) system or a bracket-based system. All adult patients, whose last orthodontic appointment before completion of treatment occurred between November 2014 and October 2016 were consecutively invited to participate in the survey during their debonding appointment. Because this was a cross-sectional study, no sample size was calculated. This was a convenience sample of all patients willing to participate in a given time period. We included adults (older than 18 years) treated exclusively with either the Invisalign system or standard brackets. We excluded patients with previous orthodontic treatment combined with orthognathic surgery, retreatments with either treatment modality, or clear aligners combined with fixed orthodontic appliances or vice versa. Otherwise, any malocclusion complexity was considered. Group 1 included Invisalign system orthodontic patients recruited from 4 private practices in Edmonton, Calgary, Vancouver, and Toronto, Canada. Group 2 originated from current patients treated exclusively with conventional fixed appliances (brackets) at the Orthodontic Graduate Clinic at the University of Alberta in Edmonton, Alberta, Canada. A small sample of this last group was retested during the 6-month retention appointment to explore short-term changes. This retest aimed to explore patient consistency in satisfaction levels after a certain period of time: 6 months. The invited patients received a pamphlet at the front desk containing all the information regarding the survey and the informed consent to be signed (Appendix 1). They had an opportunity to clarify their concerns verbally with a representative of the research project in each location. The representatives were calibrated by a member of the research project team (C.P.P.). Both groups and all invited patients had access to the e-mails and phone numbers of the research project team for further contact if they needed more clarification. Two previously validated questionnaires, the Dental Impacts on Daily Living (DIDL)14 index and the Patient Satisfaction Questionnaire (PSQ), were used.7,15 The survey answered by the patients included 94 questions in total, combined into 2 parts. Parts I and II were unified using survey software (SurveyMonkey, Palo Alto, Calif) and administered on an iPad (Apple, Cupertino, Calif) or on a paper version (the same format) as an alternative. All participants completed the survey in the waiting room after checking in for their appointment. Part I, the DIDL questionnaire, addressed 5 dimensions of life: appearance, pain, comfort, general
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performance, and eating restriction, all from the patient's perspective. This tool allowed patients to give weight to the different categories, providing a weighted dimension score, making the results more specific to each patient. Patients responded to the 36 items in a binary manner by indicating whether the statement applied to them. Each category contained between 4 and 15 statements; these items and the analysis process of the answers are listed in detail in a previous questionnaire validation article.14,16 At this point, the patients could select the sentences that applied to their daily lives (survey design in Appendix 2). The PSQ (part II) explored the nuances of patient satisfaction, investigating factors related to the doctorpatient relationship, situational aspects, psychosocial and dentofacial improvements, and dental function, with each category containing between 4 and 15 questions.7,15 In this section, the patients responded to the 58 questions using a 5-point scale, ranging from completely disagree (1 point) to completely agree (5 points). The responses were quantified and analyzed for each satisfaction factor. The questions and their validations were published in detail previously.15 The complete survey, including both parts I and II, is shown in Appendix 2. For the survey given to Invisalign patients, “fixed appliance” was replaced with “Invisalign” in all questions. Strategies to raise response rates during the retest such as telephone confirmation of the appointment or a reminder of the invitation to reanswer the survey during the 6-month appointment were used to increase the number of respondents. All data collected were blinded from the research team except for 1 member (C.P.P.) and transferred to an Excel spreadsheet (Microsoft, Redmond, Wash) for third-party statistical analysis. Neither the researchers nor the practitioners or graduate students had access to the confidential information or identifiers on the survey answers from participants.
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from the private practices. Multivariate analysis of variance (MANOVA) was used to compare all averages in each dimension and the 2 overall averages, and we investigated whether distributions were significantly different between locations. For subjective impact data analysis, the participants were grouped into 3 levels of impact: those who were satisfied (scores, 1.0-0.7), those who were relatively satisfied (scores, 0.69-0), and those who were dissatisfied (scores, \0); these cutoff values were validated by the DIDL authors.14,16 This was done for each of the 5 DIDL dimensions and also for the overall scores. The participants could check a box after a statement if they believed that the statement applied to them; not checking the box was considered a neutral response (0 value). Each dimension only contained either positive statements (11) or negative statements ( 1). P values and confidence intervals were calculated using the bootstrap method. Scores for the PSQ factors and the DIDL dimensions were compared between the Invisalign and bracketbased patients using MANOVA. It was used to simultaneously analyze the impact of many variables instead of running multiple independent t tests that would have increased the chance of type I error (false positive). A P value less than 0.05 was considered statistically significant. A bootstrap test was used to estimate the P value for the variable that was statistically significant in MANOVA. A reliability test was applied at different times, immediately after debonding and 6 months after the active treatment; the intention was to detect a trend in the bracket-based participants' answers at a 6-month reassessment. The intraclass correlation coefficient (ICC) was used and interpreted according to the guidelines of Portney and Watkins17: 0-0.2, poor agreement; 0.3-0.4, fair agreement; 0.5-0.6, moderate agreement; 0.7-0.8, strong agreement; and more than 0.8, almost perfect agreement.
Statistical analysis
The Statistical Package for the Social Sciences (version 24; IBM, Armonk, NY) was used for statistical analysis, and the data were analyzed by an independent statistical service. The DIDL answers to each question were categorized as positive (1), negative ( 1), or neutral (0) and then averaged for each dimension, according to the validated method.14,16 Each dimension score was normalized based on the weighting the patient gave it, and the weighted scores for each dimension were totalled. Tests were carried out to determine whether there was a statistical difference between the answers of patients
RESULTS
The survey was open during a 22-month period, and consecutive patients were invited to participate. Although initially 145 patients participated, the response rate was 84.1%. Thirteen participants from the private practice cohort and 10 from the university cohort did not complete the survey properly and were later excluded from the analysis. Eighteen patients requested to answer the survey on the paper version; they were not comfortable with the tablet form. Data from a total of 122 participants were included; from these participants, 3 sociodemographic variables were
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DISCUSSION
In this project, we compared perceptions of treatment satisfaction and the dimensions that changed in the patient's QoL immediately after orthodontic treatment between those who had the Invisalign system or conventional brackets. In general, after Invisalign treatment, these patients felt satisfied overall. These results agreed with other
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PATIENT DEMOGRAPHICS Invisalign
NUMBER OF PATIENTS
investigated: sex, age range, and location. A total of 33 men (27%) and 89 women (73%) participated (Fig 1). The mean and mode age ranges were between 18 and 25 years. The average responses between the private practices at Edmonton, Calgary, Vancouver, and Toronto were compared. These responses were statistically similar (P \ 0.05). Hence, all Invisalign data were considered to come from 1 location, called “private practices.” Appendix 3 shows the distribution of patients by location. Figure 2 shows a comparison of the average DIDL dimension scores (on a scale of 1-0 or 0-1), with their standard deviations, between patients who had Invisalign or bracket-based treatment. MANOVA analysis indicated that the eating and chewing dimension was significantly different between the 2 treatment modalities (P 5 0.047), with 47% of Invisalign patients reporting 100% satisfaction in this dimension compared with 24% of bracket-based patients reporting 100% satisfaction. Since the sample sizes for the private practices and the University of Alberta were not similar, we applied a nonparametric method (bootstrap test) to estimate P values for comparing average eating and chewing dimensions. The bootstrap test showed a P value of 0.051, which indicated weak evidence of a mean eating and chewing difference between bracket-based and Invisalign patients. Figure 3 is the comparison of the average PSQ factor scores (on a 5-point scale), with their standard deviations, between patients who had Invisalign treatment and those who had bracket-based treatment. MANOVA analysis indicated no significant difference in any factor (P 5 0.360). Twelve patients who had bracket-based treatment were retested. The ICC values immediately after debonding and 6 months after treatment showed that the categories of oral comfort (ICC, 0.71), general performance (ICC, 0.755), situational (ICC, 0.80), and doctor-patient relationship (ICC, 0.75) had strong correlations. However, the dental function (ICC, 0.51), psychosocial improvement (ICC, 0.51), and dentofacial improvement (ICC, 0.31) categories fairly agreed between the 2 times.
Standard bracket-based
Male
Female
41 89
81 33 TREATMENT
GENDER
Fig 1. Demographics.
studies.18 The bracket-based patients also reported a statistically similar level of satisfaction, which agreed with previous studies that showed that patients are satisfied with the results of treatment with fixed appliances.7,8 The high levels of satisfaction with both treatment modalities could have been partly because the patients were happy to have finished treatment regardless of the appliance used, since the survey was completed immediately after debonding, or because each patient chose to be treated with Invisalign or brackets, so after making the decision, this no longer influenced satisfaction. However, over 90% of the patients in both groups said that they were willing to redo treatment if necessary. These results contrast with a previous study that showed that Invisalign patients had a higher level of satisfaction than did bracketbased patients.12 An assumption for the discrepancy could be that the authors assessed their patients using binary answers (yes or no).12 When focusing on QoL, the patients from both techniques were satisfied with the results; this agrees with previous studies.11,12 Patient-doctor-staff relationship had the highest mean score of the PSQ factors for both Invisalign and bracket-based patients (means, 4.4 and 5, respectively), suggesting that it had a strong influence on patient satisfaction. This finding agrees with previous studies15,19 that have explored the importance of the doctor-patient relationship and the need for orthodontists to create a patient-centered practice.20 Previously, we had postulated that the high satisfaction rate of Invisalign patients was due to the clear, removable, and more esthetic aligners21 coupled with the idea that the Millennial generation places much importance on image.22 However, our results show that patients who had bracket-based treatment were just as satisfied with appearance, and dentofacial and psychosocial improvements as were the patients treated
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DIDL Dimensions 1.2 1 0.8 0.6 0.4 0.2 0 -0.2 -0.4
Appearance
Pain
Comfort Invisalign
Performance
Eating & Chewing All Dimensions (Weighted)
Standard Bracket-Based
Fig 2. DIDL dimension comparison between Invisalign and standard bracket-based patients.
Patient Satisfaction Questionnaire 6 5 4 3 2 1 0 Doctor-Patient Relationship
Situational Aspects
Dentofacial Improvement Invisalign
Psychosocial Improvement
Dental Function
Residual Category
Standard Bracket-Based
Fig 3. PSQ factor comparison between Invisalign and standard bracket-based patients.
with Invisalign. Although appearance is a major reason to seek orthodontic treatment, patient satisfaction was comparable between patients who had standard bracket-based and Invisalign treatment.18,23 As with any research using a survey to gather data, this study had a few limitations. Many factors—eg, orthodontists’ unwillingness to use the survey in their office, the length of the questionnaires (94 questions), time limitations of the patients and short appointments, convenience sampling, and patient concerns regarding blinding of their responses—influenced their willingness to participate in the survey. These limitations were discussed in detail in a related previous article.21 These factors compromised our response rate, limiting the
strategies to raise the number of participants.24 Although the participants had access to the research team by e-mail or phone, they preferred to clarify their concerns with the front desk staff. The combination of the 2 questionnaires and their order in the long survey could have affected the participants' answers and played a role on the completeness of the survey. We accessed satisfaction and OHRQoL without controlling for the severity of malocclusion or treatment duration, which could have affected the outcome significantly. Further research correlating patient satisfaction and QoL with orthodontic treatment complexity could show different levels of satisfaction.
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The differences in location and provider, since patients from 4 private practices and a university setting (orthodontic graduate program) were surveyed, could have influenced the participants' willingness to participate in the survey and the satisfaction levels in general; this is a limitation of our study. It is unknown whether those who volunteered to participate in this project were inherently different from those who did not. Hence, our results should not be freely generalized. The retest done for consistency purposes could just be interpreted as a trend, since the number of participants who agreed to reanswer the survey was low (10%). These responses were only for the standard bracket-based group. In addition, the paper survey and the tablets available to answer the survey were the sole options; offering the survey via e-mail could have raised the response rate. The survey Web site (https://www. surveymonkey.com) and the touch-screen tablets contributed to the easy and fast answers; however, inconsistencies or connection issues with the online survey software could be why some incomplete questionnaires were excluded from the study. CONCLUSIONS
In the sample of patients surveyed to assess satisfaction and OHRQoL, both bracket-based and Invisalign treated patients had statistically similar satisfaction outcomes across all dimensions analyzed, except for eating and chewing: the Invisalign group reported more satisfaction. Patient satisfaction remained relatively similar 6 months later for the bracket-type treatment. ACKNOWLEDGMENTS
We thank the patients for their time and availability for completing the survey; the orthodontists from the private practices for engaging their teams in this project; and Susan Helwig, Nikki Gartner, and Helena McGill for collaborating on the data collection process. SUPPLEMENTARY DATA
Supplementary data related to this article can be found online at https://doi.org/10.1016/j.ajodo.2018.01.013. REFERENCES 1. Al-Omiri MK, Abu Alhaija ES. Factors affecting patient satisfaction after orthodontic treatment. Angle Orthod 2006;76:422-31. 2. Anderson LE, Arruda A, Inglehart MR. Adolescent patients' treatment motivation and satisfaction with orthodontic treatment. Do possible selves matter? Angle Orthod 2009;79:821-7. 3. Bennadi D, Reddy CV. Oral health related quality of life. J Int Soc Prev Community Dent 2013;3:1-6.
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4. Bennett ME, Michaels C, O'Brien K, Weyant R, Phillips C, Dryland K. Measuring beliefs about orthodontic treatment: a questionnaire approach. J Public Health Dent 1997;57:215-23. 5. Shaw WC, O'Brien KD, Richmond S. Quality control in orthodontics: factors influencing the receipt of orthodontic treatment. Br Dent J 1991;170:66-8. 6. Feldmann I. Satisfaction with orthodontic treatment outcome. Angle Orthod 2014;84:581-7. 7. Bos A, Vosselman N, Hoogstraten J, Prahl-Andersen B. Patient compliance: a determinant of patient satisfaction? Angle Orthod 2005;75:526-31. 8. Mollov ND, Lindauer SJ, Best AM, Shroff B, Tufekci E. Patient attitudes toward retention and perceptions of treatment success. Angle Orthod 2010;80:468-73. 9. Zhang M, McGrath C, H€agg U. Patients' expectations and experiences of fixed orthodontic appliance therapy. Impact on quality of life. Angle Orthod 2007;77:318-22. 10. Lee YM, Nguyen TN, Giang BT, Li I. Effects of orthodontic treatment on self confidence: perspective survey by dental hygiene students. Can J Dent Hygiene 2011;45:185-90. 11. Schaefer I, Braumann B. Halitosis, oral health and quality of life during treatment with Invisalign(Ò) and the effect of a low-dose chlorhexidine solution. J Orofac Orthop 2010;71:430-41. 12. Azaripour A, Weusmann J, Mahmoodi B, Peppas D, Gerhold-Ay A, Van Noorden CJ, et al. Braces versus Invisalign(Ò): gingival parameters and patients' satisfaction during treatment: a cross-sectional study. BMC Oral Health 2015;15:69. 13. Miethke RR, Vogt S. A comparison of the periodontal health of patients during treatment with the Invisalign system and with fixed orthodontic appliances. J Orofac Orthop 2005;66:219-29. 14. Leao A, Sheihaml A. Relation between clinical dental status and subjective impacts on daily living. R. J Dent Res 1995;74:1408-13. 15. Bos A, Hoogstraten J, Prahl-Andersen B. The theory of reasoned action and patient compliance during orthodontic treatment. Community Dent Oral Epidemiol 2005;33:419-26. 16. Leao A, Sheiham A. Relation between clinical dental status and subjective impacts on daily living. J Dent Res 1995;74:1408-13. 17. Portney L. Foundations of clinical research: applications to practice. 3rd ed. Upper Saddle River, NJ: Prentice Hall; 2009. 18. Miller KB, McGorray SP, Womack R, Quintero JC, Perelmuter M, Gibson J, et al. A comparison of treatment impacts between Invisalign aligner and fixed appliance therapy during the first week of treatment. Am J Orthod Dentofacial Orthop 2007;131:302.e1-9. 19. Sinha PK, Nanda RS, McNeil DW. Perceived orthodontist behaviors that predict patient satisfaction, orthodontist-patient relationship, and patient adherence in orthodontic treatment. Am J Orthod Dentofacial Orthop 1996;110:370-7. 20. Dorr Goold S, Lipkin M Jr. The doctor-patient relationship: challenges, opportunities, and strategies. J Gen Intern Med 1999; 14(Suppl 1):S26-33. 21. Pacheco-Pereira C, Brandelli J, Flores-Mir C. Patient satisfaction and quality of life changes immediately after Invisalign treatment. Am J Orthod Dentofacial Orthop 2018;153:834-41. 22. Twenge JM, Campbell WK, Freeman EC. Generational differences in young adults' life goals, concern for others, and civic orientation, 1966-2009. J Pers Soc Psychol 2012;102:1045-62. 23. Williams AC, Shah H, Sandy JR, Travess HC. Patients' motivations for treatment and their experiences of orthodontic preparation for orthognathic surgery. J Orthod 2005;32:191-202. 24. Sitzia J, Wood N. Response rate in patient satisfaction research: an analysis of 210 published studies. Int J Qual Health Care 1998;10: 311-7.
American Journal of Orthodontics and Dentofacial Orthopedics
Patient satisfaction and quality of life status after 2 treatment modalities: Invisalign and conventional fixed appliances Carlos Flores-Mir, Jeremy Brandelli, and Camila Pacheco-Pereira Edmonton, Alberta, Canada Introduction: Our objectives were to assess patient satisfaction and quality of life among adults via 2 validated comprehensive questionnaires and to compare patient satisfaction and status in oral health-related quality of life immediately after orthodontic treatment in patients treated with Invisalign (Align Technology, San Jose, Calif) and those who received standard bracket-based treatment. Methods: Adult patients (n 5 145) treated with bracketbased or Invisalign therapy were recruited from several private practices and a university clinic. The survey comprised a combination of the Dental Impacts on Daily Living index and the Patient Satisfaction Questionnaire. This 94-question assessment focused on various dimensions of satisfaction and quality of life. Multivariate analysis of variance and the bootstrap test were applied. A reliability analysis was used to assess responses at a 6-month follow-up for a small sample of patients. Results: Finally, 122 patients were assessed. The multivariate analysis of variance analysis showed that the eating and chewing dimension was significantly different between the 2 groups (Invisalign, 49%; bracket based, 24%; P 5 0.047). No significant difference in any other satisfaction factors (all, P . 0.05) was identified. The follow-up assessment was only possible in a small sample of the bracket group; it showed adequate reliability values on the categories of oral comfort (intraclass correlation coefficient [ICC], 0.71), general performance (ICC, 0.755), situational (ICC, 0.80), and doctor-patient relationship (ICC, 0.75). Conclusions: Of the patients surveyed to assess their satisfaction and oral health-related quality of life immediately after completion of their orthodontic treatment, both the bracket-based and Invisalign treated patients had statistically similar satisfaction outcomes across all dimensions analyzed, except for eating and chewing: the Invisalign group reported more satisfaction. Patient satisfaction remained relatively similar 6 months later for the bracket-type treatment. (Am J Orthod Dentofacial Orthop 2018;154:639-44)
P
atient satisfaction, as related to oral health care, can be defined as a patient's personal evaluation of the services provided to him or her.1 It can be used as 1 measure of the overall quality of health care; therefore, it has resulted in increased interest in quantifying and qualifying patient satisfaction with dental
From the School of Dentistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada All authors completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. They reported that the 2015 North America Align Research Award Program (number RES0026582) supported this work. The funding agency did not influence the interpretation of the surveys. Dr. Pacheco-Pereira reported personal fees from Align Technology Inc, during the conduct of the study. Address correspondence to: Camila Pacheco-Pereira, School of Dentistry, Faculty of Medicine and Dentistry, 5-533 Edmonton Clinic Health Academy, 11405-87 Avenue NW, University of Alberta, Edmonton, AB, Canada T6G 1C9; e-mail, [email protected]. Submitted, October 2017; revised and accepted, January 2018. 0889-5406/$36.00 Ó 2018 by the American Association of Orthodontists. All rights reserved. https://doi.org/10.1016/j.ajodo.2018.01.013
treatment.2 Nonetheless, due to different motivations and expectations for seeking oral health care, professional assessments of treatment outcomes may differ from those of their patients.3,4 This is also true for orthodontic treatment, where motivation to seek treatment includes esthetics, improved dental function, and psychological benefit; these motivations occur at different degrees in different patients, and younger patients may even lack motivation for treatment since they are brought in by their parents.4,5 Previous studies examining patient satisfaction with fixed appliances have suggested that some patients may experience pain and discomfort immediately after orthodontic appliances are bonded as well as sometimes after regular visits. This was negatively correlated with patient satisfaction.6 However, at the end, the vast majority of patients were satisfied with the outcomes of their orthodontic treatment.7,8 Furthermore, although temporary negative effects on function and social and 639
Flores-Mir, Brandelli, and Pacheco-Pereira
640
emotional well-being are expected as side effects of standard bracket-based treatment, these effects were significantly less than what patients expected before starting treatment.9 Clear aligners were introduced to provide orthodontic treatment with a more esthetic, removable appliance. However, a previous study showed that 50% of patients undergoing Invisalign (Align Technology, San Jose, Calif) treatment were self-conscious about their appearance during treatment.10 Most patients reported satisfaction with the results of their orthodontic treatment and improvement in self-confidence after treatment.10 Furthermore, oral health-related quality of life (OHRQoL) was only minimally affected during treatment.11 There are many factors to consider when choosing between clear aligners and conventional bracket-based treatment. The ability to remove the clear aligners may make it easier for patients to maintain good oral hygiene,11 but studies have shown conflicting results. One study suggested poorer gingival health in the bracket-based group compared with the Invisalign group but equal plaque accumulation between the 2 groups in a sample of adults and children.12 Another study showed that subjects with the fixed appliance modality retained more plaque, but the gingival health between the 2 treatments was nearly identical.13 Patient satisfaction was reported to be higher in the Invisalign group, with these patients reporting more willingness to redo the same treatment, fewer changes in eating habits, and less decrease in overall well-being during treatment.12 Few studies have combined the effects of different treatment modalities on adult patient satisfaction and quality of life (QoL). Most previous studies assessing satisfaction applied nonvalidated questionnaires; some used only 1 question or a few questions addressing satisfaction as an overall statement. These tools could be considered susceptible to subjectivity and likely compromise the reliability or internal validity of the questions. Therefore, in this study, we aimed to assess adult patients' satisfaction and OHRQoL status immediately after orthodontic treatment via 2 validated, wide-ranging questionnaires and to compare patient satisfaction and changes in OHRQoL immediately after orthodontic treatment on patients who had Invisalign or bracket-type treatment. MATERIAL AND METHODS
Approval from the Research Ethics Board at the University of Alberta in Canada was granted for the protocol and informed consent process of this study (Pro00056779). An observational cross-sectional study was planned to compare the factors related to treatment
November 2018 Vol 154 Issue 5
satisfaction and OHRQoL status in adult orthodontic patients treated with either the Invisalign (Align Technology, San Jose, Calif) system or a bracket-based system. All adult patients, whose last orthodontic appointment before completion of treatment occurred between November 2014 and October 2016 were consecutively invited to participate in the survey during their debonding appointment. Because this was a cross-sectional study, no sample size was calculated. This was a convenience sample of all patients willing to participate in a given time period. We included adults (older than 18 years) treated exclusively with either the Invisalign system or standard brackets. We excluded patients with previous orthodontic treatment combined with orthognathic surgery, retreatments with either treatment modality, or clear aligners combined with fixed orthodontic appliances or vice versa. Otherwise, any malocclusion complexity was considered. Group 1 included Invisalign system orthodontic patients recruited from 4 private practices in Edmonton, Calgary, Vancouver, and Toronto, Canada. Group 2 originated from current patients treated exclusively with conventional fixed appliances (brackets) at the Orthodontic Graduate Clinic at the University of Alberta in Edmonton, Alberta, Canada. A small sample of this last group was retested during the 6-month retention appointment to explore short-term changes. This retest aimed to explore patient consistency in satisfaction levels after a certain period of time: 6 months. The invited patients received a pamphlet at the front desk containing all the information regarding the survey and the informed consent to be signed (Appendix 1). They had an opportunity to clarify their concerns verbally with a representative of the research project in each location. The representatives were calibrated by a member of the research project team (C.P.P.). Both groups and all invited patients had access to the e-mails and phone numbers of the research project team for further contact if they needed more clarification. Two previously validated questionnaires, the Dental Impacts on Daily Living (DIDL)14 index and the Patient Satisfaction Questionnaire (PSQ), were used.7,15 The survey answered by the patients included 94 questions in total, combined into 2 parts. Parts I and II were unified using survey software (SurveyMonkey, Palo Alto, Calif) and administered on an iPad (Apple, Cupertino, Calif) or on a paper version (the same format) as an alternative. All participants completed the survey in the waiting room after checking in for their appointment. Part I, the DIDL questionnaire, addressed 5 dimensions of life: appearance, pain, comfort, general
American Journal of Orthodontics and Dentofacial Orthopedics
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performance, and eating restriction, all from the patient's perspective. This tool allowed patients to give weight to the different categories, providing a weighted dimension score, making the results more specific to each patient. Patients responded to the 36 items in a binary manner by indicating whether the statement applied to them. Each category contained between 4 and 15 statements; these items and the analysis process of the answers are listed in detail in a previous questionnaire validation article.14,16 At this point, the patients could select the sentences that applied to their daily lives (survey design in Appendix 2). The PSQ (part II) explored the nuances of patient satisfaction, investigating factors related to the doctorpatient relationship, situational aspects, psychosocial and dentofacial improvements, and dental function, with each category containing between 4 and 15 questions.7,15 In this section, the patients responded to the 58 questions using a 5-point scale, ranging from completely disagree (1 point) to completely agree (5 points). The responses were quantified and analyzed for each satisfaction factor. The questions and their validations were published in detail previously.15 The complete survey, including both parts I and II, is shown in Appendix 2. For the survey given to Invisalign patients, “fixed appliance” was replaced with “Invisalign” in all questions. Strategies to raise response rates during the retest such as telephone confirmation of the appointment or a reminder of the invitation to reanswer the survey during the 6-month appointment were used to increase the number of respondents. All data collected were blinded from the research team except for 1 member (C.P.P.) and transferred to an Excel spreadsheet (Microsoft, Redmond, Wash) for third-party statistical analysis. Neither the researchers nor the practitioners or graduate students had access to the confidential information or identifiers on the survey answers from participants.
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from the private practices. Multivariate analysis of variance (MANOVA) was used to compare all averages in each dimension and the 2 overall averages, and we investigated whether distributions were significantly different between locations. For subjective impact data analysis, the participants were grouped into 3 levels of impact: those who were satisfied (scores, 1.0-0.7), those who were relatively satisfied (scores, 0.69-0), and those who were dissatisfied (scores, \0); these cutoff values were validated by the DIDL authors.14,16 This was done for each of the 5 DIDL dimensions and also for the overall scores. The participants could check a box after a statement if they believed that the statement applied to them; not checking the box was considered a neutral response (0 value). Each dimension only contained either positive statements (11) or negative statements ( 1). P values and confidence intervals were calculated using the bootstrap method. Scores for the PSQ factors and the DIDL dimensions were compared between the Invisalign and bracketbased patients using MANOVA. It was used to simultaneously analyze the impact of many variables instead of running multiple independent t tests that would have increased the chance of type I error (false positive). A P value less than 0.05 was considered statistically significant. A bootstrap test was used to estimate the P value for the variable that was statistically significant in MANOVA. A reliability test was applied at different times, immediately after debonding and 6 months after the active treatment; the intention was to detect a trend in the bracket-based participants' answers at a 6-month reassessment. The intraclass correlation coefficient (ICC) was used and interpreted according to the guidelines of Portney and Watkins17: 0-0.2, poor agreement; 0.3-0.4, fair agreement; 0.5-0.6, moderate agreement; 0.7-0.8, strong agreement; and more than 0.8, almost perfect agreement.
Statistical analysis
The Statistical Package for the Social Sciences (version 24; IBM, Armonk, NY) was used for statistical analysis, and the data were analyzed by an independent statistical service. The DIDL answers to each question were categorized as positive (1), negative ( 1), or neutral (0) and then averaged for each dimension, according to the validated method.14,16 Each dimension score was normalized based on the weighting the patient gave it, and the weighted scores for each dimension were totalled. Tests were carried out to determine whether there was a statistical difference between the answers of patients
RESULTS
The survey was open during a 22-month period, and consecutive patients were invited to participate. Although initially 145 patients participated, the response rate was 84.1%. Thirteen participants from the private practice cohort and 10 from the university cohort did not complete the survey properly and were later excluded from the analysis. Eighteen patients requested to answer the survey on the paper version; they were not comfortable with the tablet form. Data from a total of 122 participants were included; from these participants, 3 sociodemographic variables were
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DISCUSSION
In this project, we compared perceptions of treatment satisfaction and the dimensions that changed in the patient's QoL immediately after orthodontic treatment between those who had the Invisalign system or conventional brackets. In general, after Invisalign treatment, these patients felt satisfied overall. These results agreed with other
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PATIENT DEMOGRAPHICS Invisalign
NUMBER OF PATIENTS
investigated: sex, age range, and location. A total of 33 men (27%) and 89 women (73%) participated (Fig 1). The mean and mode age ranges were between 18 and 25 years. The average responses between the private practices at Edmonton, Calgary, Vancouver, and Toronto were compared. These responses were statistically similar (P \ 0.05). Hence, all Invisalign data were considered to come from 1 location, called “private practices.” Appendix 3 shows the distribution of patients by location. Figure 2 shows a comparison of the average DIDL dimension scores (on a scale of 1-0 or 0-1), with their standard deviations, between patients who had Invisalign or bracket-based treatment. MANOVA analysis indicated that the eating and chewing dimension was significantly different between the 2 treatment modalities (P 5 0.047), with 47% of Invisalign patients reporting 100% satisfaction in this dimension compared with 24% of bracket-based patients reporting 100% satisfaction. Since the sample sizes for the private practices and the University of Alberta were not similar, we applied a nonparametric method (bootstrap test) to estimate P values for comparing average eating and chewing dimensions. The bootstrap test showed a P value of 0.051, which indicated weak evidence of a mean eating and chewing difference between bracket-based and Invisalign patients. Figure 3 is the comparison of the average PSQ factor scores (on a 5-point scale), with their standard deviations, between patients who had Invisalign treatment and those who had bracket-based treatment. MANOVA analysis indicated no significant difference in any factor (P 5 0.360). Twelve patients who had bracket-based treatment were retested. The ICC values immediately after debonding and 6 months after treatment showed that the categories of oral comfort (ICC, 0.71), general performance (ICC, 0.755), situational (ICC, 0.80), and doctor-patient relationship (ICC, 0.75) had strong correlations. However, the dental function (ICC, 0.51), psychosocial improvement (ICC, 0.51), and dentofacial improvement (ICC, 0.31) categories fairly agreed between the 2 times.
Standard bracket-based
Male
Female
41 89
81 33 TREATMENT
GENDER
Fig 1. Demographics.
studies.18 The bracket-based patients also reported a statistically similar level of satisfaction, which agreed with previous studies that showed that patients are satisfied with the results of treatment with fixed appliances.7,8 The high levels of satisfaction with both treatment modalities could have been partly because the patients were happy to have finished treatment regardless of the appliance used, since the survey was completed immediately after debonding, or because each patient chose to be treated with Invisalign or brackets, so after making the decision, this no longer influenced satisfaction. However, over 90% of the patients in both groups said that they were willing to redo treatment if necessary. These results contrast with a previous study that showed that Invisalign patients had a higher level of satisfaction than did bracketbased patients.12 An assumption for the discrepancy could be that the authors assessed their patients using binary answers (yes or no).12 When focusing on QoL, the patients from both techniques were satisfied with the results; this agrees with previous studies.11,12 Patient-doctor-staff relationship had the highest mean score of the PSQ factors for both Invisalign and bracket-based patients (means, 4.4 and 5, respectively), suggesting that it had a strong influence on patient satisfaction. This finding agrees with previous studies15,19 that have explored the importance of the doctor-patient relationship and the need for orthodontists to create a patient-centered practice.20 Previously, we had postulated that the high satisfaction rate of Invisalign patients was due to the clear, removable, and more esthetic aligners21 coupled with the idea that the Millennial generation places much importance on image.22 However, our results show that patients who had bracket-based treatment were just as satisfied with appearance, and dentofacial and psychosocial improvements as were the patients treated
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DIDL Dimensions 1.2 1 0.8 0.6 0.4 0.2 0 -0.2 -0.4
Appearance
Pain
Comfort Invisalign
Performance
Eating & Chewing All Dimensions (Weighted)
Standard Bracket-Based
Fig 2. DIDL dimension comparison between Invisalign and standard bracket-based patients.
Patient Satisfaction Questionnaire 6 5 4 3 2 1 0 Doctor-Patient Relationship
Situational Aspects
Dentofacial Improvement Invisalign
Psychosocial Improvement
Dental Function
Residual Category
Standard Bracket-Based
Fig 3. PSQ factor comparison between Invisalign and standard bracket-based patients.
with Invisalign. Although appearance is a major reason to seek orthodontic treatment, patient satisfaction was comparable between patients who had standard bracket-based and Invisalign treatment.18,23 As with any research using a survey to gather data, this study had a few limitations. Many factors—eg, orthodontists’ unwillingness to use the survey in their office, the length of the questionnaires (94 questions), time limitations of the patients and short appointments, convenience sampling, and patient concerns regarding blinding of their responses—influenced their willingness to participate in the survey. These limitations were discussed in detail in a related previous article.21 These factors compromised our response rate, limiting the
strategies to raise the number of participants.24 Although the participants had access to the research team by e-mail or phone, they preferred to clarify their concerns with the front desk staff. The combination of the 2 questionnaires and their order in the long survey could have affected the participants' answers and played a role on the completeness of the survey. We accessed satisfaction and OHRQoL without controlling for the severity of malocclusion or treatment duration, which could have affected the outcome significantly. Further research correlating patient satisfaction and QoL with orthodontic treatment complexity could show different levels of satisfaction.
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The differences in location and provider, since patients from 4 private practices and a university setting (orthodontic graduate program) were surveyed, could have influenced the participants' willingness to participate in the survey and the satisfaction levels in general; this is a limitation of our study. It is unknown whether those who volunteered to participate in this project were inherently different from those who did not. Hence, our results should not be freely generalized. The retest done for consistency purposes could just be interpreted as a trend, since the number of participants who agreed to reanswer the survey was low (10%). These responses were only for the standard bracket-based group. In addition, the paper survey and the tablets available to answer the survey were the sole options; offering the survey via e-mail could have raised the response rate. The survey Web site (https://www. surveymonkey.com) and the touch-screen tablets contributed to the easy and fast answers; however, inconsistencies or connection issues with the online survey software could be why some incomplete questionnaires were excluded from the study. CONCLUSIONS
In the sample of patients surveyed to assess satisfaction and OHRQoL, both bracket-based and Invisalign treated patients had statistically similar satisfaction outcomes across all dimensions analyzed, except for eating and chewing: the Invisalign group reported more satisfaction. Patient satisfaction remained relatively similar 6 months later for the bracket-type treatment. ACKNOWLEDGMENTS
We thank the patients for their time and availability for completing the survey; the orthodontists from the private practices for engaging their teams in this project; and Susan Helwig, Nikki Gartner, and Helena McGill for collaborating on the data collection process. SUPPLEMENTARY DATA
Supplementary data related to this article can be found online at https://doi.org/10.1016/j.ajodo.2018.01.013. REFERENCES 1. Al-Omiri MK, Abu Alhaija ES. Factors affecting patient satisfaction after orthodontic treatment. Angle Orthod 2006;76:422-31. 2. Anderson LE, Arruda A, Inglehart MR. Adolescent patients' treatment motivation and satisfaction with orthodontic treatment. Do possible selves matter? Angle Orthod 2009;79:821-7. 3. Bennadi D, Reddy CV. Oral health related quality of life. J Int Soc Prev Community Dent 2013;3:1-6.
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4. Bennett ME, Michaels C, O'Brien K, Weyant R, Phillips C, Dryland K. Measuring beliefs about orthodontic treatment: a questionnaire approach. J Public Health Dent 1997;57:215-23. 5. Shaw WC, O'Brien KD, Richmond S. Quality control in orthodontics: factors influencing the receipt of orthodontic treatment. Br Dent J 1991;170:66-8. 6. Feldmann I. Satisfaction with orthodontic treatment outcome. Angle Orthod 2014;84:581-7. 7. Bos A, Vosselman N, Hoogstraten J, Prahl-Andersen B. Patient compliance: a determinant of patient satisfaction? Angle Orthod 2005;75:526-31. 8. Mollov ND, Lindauer SJ, Best AM, Shroff B, Tufekci E. Patient attitudes toward retention and perceptions of treatment success. Angle Orthod 2010;80:468-73. 9. Zhang M, McGrath C, H€agg U. Patients' expectations and experiences of fixed orthodontic appliance therapy. Impact on quality of life. Angle Orthod 2007;77:318-22. 10. Lee YM, Nguyen TN, Giang BT, Li I. Effects of orthodontic treatment on self confidence: perspective survey by dental hygiene students. Can J Dent Hygiene 2011;45:185-90. 11. Schaefer I, Braumann B. Halitosis, oral health and quality of life during treatment with Invisalign(Ò) and the effect of a low-dose chlorhexidine solution. J Orofac Orthop 2010;71:430-41. 12. Azaripour A, Weusmann J, Mahmoodi B, Peppas D, Gerhold-Ay A, Van Noorden CJ, et al. Braces versus Invisalign(Ò): gingival parameters and patients' satisfaction during treatment: a cross-sectional study. BMC Oral Health 2015;15:69. 13. Miethke RR, Vogt S. A comparison of the periodontal health of patients during treatment with the Invisalign system and with fixed orthodontic appliances. J Orofac Orthop 2005;66:219-29. 14. Leao A, Sheihaml A. Relation between clinical dental status and subjective impacts on daily living. R. J Dent Res 1995;74:1408-13. 15. Bos A, Hoogstraten J, Prahl-Andersen B. The theory of reasoned action and patient compliance during orthodontic treatment. Community Dent Oral Epidemiol 2005;33:419-26. 16. Leao A, Sheiham A. Relation between clinical dental status and subjective impacts on daily living. J Dent Res 1995;74:1408-13. 17. Portney L. Foundations of clinical research: applications to practice. 3rd ed. Upper Saddle River, NJ: Prentice Hall; 2009. 18. Miller KB, McGorray SP, Womack R, Quintero JC, Perelmuter M, Gibson J, et al. A comparison of treatment impacts between Invisalign aligner and fixed appliance therapy during the first week of treatment. Am J Orthod Dentofacial Orthop 2007;131:302.e1-9. 19. Sinha PK, Nanda RS, McNeil DW. Perceived orthodontist behaviors that predict patient satisfaction, orthodontist-patient relationship, and patient adherence in orthodontic treatment. Am J Orthod Dentofacial Orthop 1996;110:370-7. 20. Dorr Goold S, Lipkin M Jr. The doctor-patient relationship: challenges, opportunities, and strategies. J Gen Intern Med 1999; 14(Suppl 1):S26-33. 21. Pacheco-Pereira C, Brandelli J, Flores-Mir C. Patient satisfaction and quality of life changes immediately after Invisalign treatment. Am J Orthod Dentofacial Orthop 2018;153:834-41. 22. Twenge JM, Campbell WK, Freeman EC. Generational differences in young adults' life goals, concern for others, and civic orientation, 1966-2009. J Pers Soc Psychol 2012;102:1045-62. 23. Williams AC, Shah H, Sandy JR, Travess HC. Patients' motivations for treatment and their experiences of orthodontic preparation for orthognathic surgery. J Orthod 2005;32:191-202. 24. Sitzia J, Wood N. Response rate in patient satisfaction research: an analysis of 210 published studies. Int J Qual Health Care 1998;10: 311-7.
American Journal of Orthodontics and Dentofacial Orthopedics