A Cross-sectional Study to Determine Whether Adjustment to an Ostomy Can Predict Health-related and/or Overall Quality of Life
Ostomy-specific adjustment may or may not predict health-related quality of life (HRQoL) and/or overall quality of life (QoL). A cross-sectional study was conducted among patients recruited from the customer registers of 8 surgical suppliers and pharmacies across Norway between November 2010 and March 2011 to determine which of the 34 items of the Ostomy Adjustment Scale (OAS) are the strongest predictors for HRQoL and overall QoL and to determine the HRQoL and overall QoL of individuals with an ostomy compared to a control group representing the general population.
Persons who were >18 years old; had a permanent colostomy, ileostomy, or urostomy for >3 months; and could read and write Norwegian were invited to participate. The participants received information about the study in a letter from the researcher and returned their demographic information (addressing gender, age, marital status, education, diagnosis, time since surgery, and ostomy type) and study questionnaires using prepaid envelopes. The 158 participants (mean age 64 years [range 29–91], 89 [56%] men and 69 [44%] women) completed and returned by mail a sociodemographic questionnaire, the 34-item OAS (questions scored on a scale of 1 to 6, totally disagree to totally agree, score range 34 to 204), the Short Form-36 (SF-36, including 2 main components [physical and mental issues] divided into 8 subscales, scored from 0 to 100), and the 16-item Quality of Life Scale (QOLS) instrument (each response scored 1 to 7, from very dissatisfied to very satisfied; total score ranging from 16 to 112). Statistical analysis, including ordinary least square regression analyses, assessed whether the OAS independently predicted the sum scores of the SF-36 (physical component summary [PCS] and mental component summary [MCS]) and the QOLS score after adjusting for age, gender, marital status, education, diagnosis, time since surgery, and ostomy type. The OAS significantly predicted the SF-36 (PCS and MCS) and QOLS scores (P <0.001). Five (5) OAS items (“living a fulfilling life,” “being free to travel where I want despite my ostomy,” “realizing that this ostomy will be there forever,” “worries about being left alone,” and “embarrassing accidents in sexual activities”) strongly predicted the composite score of the SF-36 (PCS and MCS) and QOLS measurements. The SF-36 scores in physical role functioning, general health, vitality, and MCS were lower in ostomy patients than controls (P <0.05), whereas no difference was found for QOLS. Overall, ostomy-specific adjustment may be an important predictor of HRQoL and overall QoL, with the OAS factors described above having greater influence. More research such as prospective cohort studies are needed regarding patient adjustment to an ostomy.
Several qualitative studies describe how surgical ostomies can impact all aspects of life; their themes include being different from others and learning how to live with a stoma1 and coping with an altered sense of self, living a restricted life, and overcoming resulting restrictions.2 Research regarding quality of life (QoL), including a prospective, longitudinal, multicenter study3 of follow-up programs for patients with an ostomy, seek to gain a better understanding of the impact of living with an ostomy and to develop appropriate care and long-term plans for patients with ostomies. Overall, QoL is understood to encompass satisfaction in all aspects of life, including material comfort, health, independency, recreation, and relationships with others,4,5 whereas the more specific concept of health-related quality of life (HRQoL) relates only to the effects of illness on health and well-being.6
Several instruments have been used to assess QoL related to health conditions. The 34-item Ostomy Adjustment Scale (OAS) includes the patient’s care of the ostomy, feelings about having an ostomy, leisure and work ability, opinions regarding instructions received for the ostomy, and feelings about the enterostomal therapist (ET nurse) or physician.7 Items are scored from 1 to 6 (1 = totally disagree and 6 = totally agree); the total score ranges from 34 to 204 with higher scores associated with better levels of adjustment. The psychometric properties of the OAS have shown good levels of internal consistency, as illustrated by Cronbach alpha values ranging from 0.87 to 0.95.7,8-11 Furthermore, the test-retest reliability of the OAS has been calculated in several studies using Pearson correlation with reported values ranging from 0.59-0.82.7,8,10,11 The OAS has been validated in a Norwegian population8 but has not been further validated in a clinical context.
The Short Form-36 (SF-36) measures the symptoms and functions known to be most affected by disease and treatment.12 The scale includes 8 subscales that can be divided into 2 summary scores: the physical component summary (PCS), including physical functioning, physical role functioning, bodily pain, and general health subscales; and the mental component summary (MCS), including vitality, social functioning, emotional role function, and mental health subscales. The question responses are on an ordinal scale. The subdomains are calculated into a continuous scale that ranges from 0 to 100, and the summary scores are calculated so a score of 50 with a standard deviation of 10 equals the average scores of the United States population. Higher scores are associated with better HRQoL. The SF-36 has been previously validated in Norway, and the Norwegian population norm scores for the SF-36 have been published.13
Overall QoL can be measured using the Quality of Life Scale (QOLS)14 questionnaire, which facilitates assessment of an individual’s overall satisfaction with life, such as material comfort, health, independence, recreation, and relationships with others. The 16 items are scored on a scale from 1 to 7 (1 = very dissatisfied and 7 = very satisfied, with cumulative scores ranging from 16 to 112. Higher scores are associated with a better QoL. The QOLS has been found to be valid for measuring domains of QoL across patient groups and cultures. The scale has been validated in Norway,15 and scores are available for comparison.15-17
Many cross-sectional studies have investigated HRQoL in patients with an ostomy using the SF-36 instrument and compared results with scores from a control group within the general population: a survey18 from Japan of 102 colostomy patients found significantly lower SF-36 scores in physical role functioning and social functioning scales than in the general population scores; and a study19 of 64 urostomy patients showed all SF-36 scores (except for pain) were lower than the general population. A descriptive study20 (N = 44 colostomy patients) found scores of all SF-36 scales were lower than general population scores. A longitudinal, prospective study21 among 57 patients with a loop ileostomy or permanent colostomy who completed the SF-36 found scores decreased 1 month following surgery, but all scores were higher than preoperative scores after 6 months. However, the physical role functioning, social functioning, emotional role functioning, and mental health scores were still lower than the general (reference) population after 6 months (P <0.05). A cross-sectional study22 using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) and the EORTC colorectal quality of life questionnaire (QLQ-CR38) examined the physical and mental consequences of an ostomy in 1019 rectal cancer survivors; the health status/QoL was lower in the 408 patients with an ostomy compared to those without.
The general finding is that HRQoL is slightly reduced in patients who require an ostomy, typically in the role functioning and social domain items of the instrument(s).18-21 Although knowledge is lacking regarding how ostomy-specific measures are associated with and predict HRQoL and overall QoL outcomes in patients with an ostomy, studies have found sociodemographic and clinical factors were related to HRQoL and overall QoL. The study by Furukawa et al19 of 64 urostomy patients using the SF-36 found the presence of a supportive person at home and participation in a support group were associated with better HRQoL. The descriptive survey study by Kement et al20 among 44 patients using the SF-36 indicated that gender, marital status, and household (living alone or together with partner or family) affected several SF-36 scores. The cross-sectional study by Mahjoubi et al23 found a significantly higher QoL in 38 patients with an appropriate stoma site compared to 174 patients with an inappropriate stoma site selection as measured with the EORTC 30. A cross-sectional study24 used an ostomy-specific QoL instrument in 105 patients and found significantly higher QoL in patients in whom the stoma site was marked preoperatively. In a multicenter, descriptive study of 748 patients, Baykara et al25 found significantly more skin problems, separation, and retraction of the ostomy in patients where the stoma site was not marked. Fear of leakage and altered sexual function that negatively affected QoL were noted in 1 cross-sectional study26; in another27 that used the City of Hope Quality of Life Questionnaire among 307 patients with urinary diversions, skin problems, difficulties in managing the ostomy, fear of recurrence, financial worries, family stress, and uncertainty about the future were found to negatively affect QoL. Additional cross-sectional studies found poor sleeping patterns, which may be related to fear of leakage from the equipment, were implicated in reducing HRQoL and overall QoL28; and improving self-care and inspiring hope were important factors in increasing stoma-related QoL (N = 76 ostomy patients).29 A longitudinal study11 found the fear of being dependent on other people and the uncertain nature of living with cancer are the most frequent concerns in the first 6 months after surgery.
In general, studies that have used a qualitative approach or disease-specific or health-related scales have shown patients with a stoma with limitations in their everyday living have lower HRQoL or overall QoL scores than patients unaffected by these issues.2,19,29 A case-control study30 found HRQoL can be improved if patients attend a patient education group.
In summary, a large body of research19-21,24-30 has assessed overall QoL, HRQoL, and ostomy-specific QoL in ostomy patients and several variables were noted to influence scores. However, to the authors’ knowledge, no studies have assessed ostomy-specific adjustments, HRQoL, and overall QoL in the same population of individuals and related these findings to population norms. It is also unknown whether an ostomy-specific adjustment is a predictor of HRQoL and overall QoL, which could lead to strategies that can improve the QoL of patients living with an ostomy.
Proposed relationships between ostomy-specific QoL as measured with the OAS, HRQoL as measured by the SF-36, and overall QoL measured with the QOLS are shown in Figure 1. The main purpose of this study was to assess whether ostomy-specific adjustment, assessed by the total OAS score, was a predictor for HRQoL and overall QoL, and if any specific ostomy-specific adjustments were strongly related. In addition, HRQoL and overall QoL scores were compared in a cross-sectional study among Norwegian patients with an ostomy and a control group of individuals selected from the general Norwegian population. Specifically, research questions focused on:
- Does ostomy-specific adjustment measured with the OAS predict HRQoL measured with SF-36 and overall QoL measured with the QOLS?
- Which issues of the ostomy-specific adjustments are most strongly related to HRQoL and overall QoL?
- How do ostomy patients evaluate their HRQoL and overall QoL compared to the normal Norwegian population?
Materials and Methods
Participants. In this cross-sectional survey, participants were recruited from patient registers maintained by surgical suppliers and pharmacies across Norway between November 2010 and March 2011. In Norway, all ostomy patients receive their ostomy supplies from pharmacies/ostomy suppliers. In order to reach a sufficient number of participants, 13 pharmacies/ostomy suppliers in different regions of Norway were asked to participate in the study. Study materials were sent from the pharmacies/surgical suppliers to patients who had received ostomy supplies for >3 months. Persons who were >18 years old; had a permanent colostomy, ileostomy, or urostomy for >3 months; and could read and write Norwegian were included. The exclusion criterion was having the ostomy for <3 months. The participants received information about the study in a letter from the researcher and returned their demographic information (addressing gender, age, marital status, education, diagnosis, time since surgery, and ostomy type) and study questionnaires using prepaid envelopes. Reminders were sent if materials were not returned within 3 weeks. An informed consent document was included in the cover letter for participants to sign if they decided to participate in the study. The study was conducted in accordance with the Helsinki Declaration and was approved by the Regional Committee for Medical Research Ethics in Western Norway (reference number: 2013/2029).
Sociodemographic and clinical data. Sociodemographic and clinical data were collected using a standardized form. Ostomy-specific adjustments were measured using the OAS; the SF-36 and QOLS were used to measure HRQOL and provided assessment of an individual’s overall satisfaction with life.
Statistical analysis. Continuous variables were described using means and standard deviations; categorical variables were described using numbers and percentages. For missing items in the OAS and QOLS, the average score was substituted for the mean overall score if at least half of the items were answered in both scales.15,33 Similarly, for missing items in the SF-36, the average score was used if at least half of the items in a domain were answered across the completed items with the same score.13,34 The SF-36 and QOLS scores in the cohort were compared with scores from the general population norm, adjusted for age and gender,13,15 using a 1-sample t-test. Effect sizes of these differences were calculated by subtracting the average scores of the patients from average population scores and dividing by the SDs of the patient group. These SD units were judged against the standard criteria proposed by Cohen35 as follows: trivial (<0.2), small (0.2 to <0.5), moderate (0.5 to <0.8), and large (≥0.8). Simple and multiple ordinary least square regression analyses were used to study whether the OAS sum score was a predictor of the SF-36 scores (PCS and MCS) and the QOLS score. The multiple regression analysis was adjusted for gender, age, marital status, education, diagnosis, time since surgery, and ostomy type. A model of whether the 34 OAS items predicted PCS, MCS, and QOLS and whether a composite score of these outcomes, using partial least square (PLS) regression allowing for multivariate modeling of highly correlated independent variables, also was studied.36 No independent variables other than the 34 OAS items were included in the PLS analyses. In these analyses, the outcomes all were standardized to a mean equal to zero and a SD of 1.
To assess the robustness of the findings, all models were cross-validated, excluding every fourth subject, to compare the models with each other. Statistical analyses for the PLS regression were conducted using Sirius v. 8.0 software (Pattern Recognition Systems, Bergen, Norway); all other analyses were conducted with SPSS software (version 21; IBM, Armonk, NY). P values were 2-sided, and values <0.05 were considered significant.
Eight (8) out of a possible 13 pharmacies participated. Of 217 initial questionnaires, 5 were returned to the surgical/pharmacy suppliers because of changes in the person’s health status, 54 had no response, and 158 completed questionnaires were returned (74%). The mean age of participants was 64 years (range 29–91). Overall, 89 (56%) men and 69 (44%) women participated in the study; 117 (74%) of the participants were married or cohabiting, 41 (26%) lived alone or with children or parents, 100 (63%) had primary or high school education, and 50 (32%) had college or university education. The main reason for stoma creation was cancer (77.5%), followed by inflammatory bowel disease (IBD; 59.4%) and diverticulosis, interstitial cystitis, and bowel ischemia (19.1%). Most of the respondents (130) had a fecal ostomy; the other 26 had a urostomy. One hundred, five (105, 70%) had their surgery >1 year previous, and 45 (30%) had their surgery <1 year ago. Slightly more than 3% of the questionnaires had too many omissions to be included.
OAS prediction of HRQoL and overall QoL. The average OAS score was 150.2 (SD 30.1). In the linear least square ordinary regression analysis, the OAS significantly predicted the 2 summary scores of the SF-36 and the QOLS (P <0.001 (see Table 1). This finding showed a higher OAS score indicates better levels of HRQoL and overall QoL.
Ostomy-specific adjustment and relation to HRQoL and overall QoL. Further analysis showed items regarding “living a fulfilling life,” “being free to travel where I want despite my ostomy,” “realizing that this ostomy will be there forever,” “worries about being left alone,” and “embarrassing accidents in sexual activities” were strong predictors of the composite scores of PCS, MCS, and QOLS (see Table 2).
HRQoL and overall QoL among ostomy patients compared to the control population. The average QOLS score for ostomy patients in the present study was similar to the score of a Norwegian population norm, but the ostomy patients scored significantly lower on the SF-36 domains of physical role functioning, general health, vitality, and MCS (P <0.05) (see Table 3).
To the authors’ knowledge, this is the first study to show an association between ostomy adjustment and QoL outcomes. This study found the total OAS score was an important predictor of the summary score of the SF-36 and the QOLS, corresponding to moderate effect sizes.18 Some of the OAS items were better predictors for QoL than others, such as “living a fulfilling life,” “being free to travel,” “realizing that my ostomy will be permanent,” “worries about being left alone,” and “worries about sexual function.” Although the SF-36 scores regarding physical role functioning, general health, vitality, and MCS were significantly lower compared with those of the general population, no significant difference was found regarding the other SF-36 measures and QOLS results.
Observational studies have investigated associations between symptoms, diagnosis, or sociodemographic factors and QoL24 or the prevalence of complications. Such studies include the descriptive study by Mahjoubi et al37 of 330 patients with a colostomy; however, this study was not specific to the adjustment of patients to life with an ostomy. The adjustment to the ostomy is an ongoing process and, in using the OAS, the degree of adjustment and its impact on QoL outcomes can be measured. The findings of the current study can be used to understand how the patient adjusts to life with an ostomy in general and how the process impacts QoL outcomes. A low total OAS score indicates QoL scores also are lowered. The strongest predictors of QoL outcomes in this study can be thought of as an important group of factors regarding how patients adjust to the physical, psychological, and social impact of having an ostomy. In the analysis, items in the OAS that were the most important regarding QoL outcomes were determined. The association between a low score in OAS items, such as “living a fulfilling life,” “being free to travel,” “realizing that this ostomy will be permanent,” “worries about being left alone,” and “worries about sexual function” significantly influenced both physical and mental health status and overall QoL levels.
No direct comparative studies have been published, but other observational studies ranging from 57 to 178 patients have found factors such as fear of stoma leaks, skin problems in the parastomal area, and reduced sexual function negatively influence HRQoL.19-21,23,33 The HRQoL of ostomy patients was compared with the general population in the present study, and the findings were consistent with the longitudinal study by Ito et al38 of 18 successfully treated rectal cancer patients. In both studies, physical role function in ostomy patients was lower than in the general population; Ito et al also found in a cross-sectional study18 that physical role function (P <0.001)and social role function (P <0.01) were significantly lower than the general population. Furthermore, the mental function score of ostomy patients was statistically significantly lower (P = 0.016) than the control group score in the present study, which also is consistent with findings from the longitudinal study by Carlsson et al,21 where ostomy patients scored significantly lower than the norm population in emotional role function, social function, and mental health domains at 1 and 3 months after surgery. With the exception of the mental health domain, HRQoL scores were consistently lower than the general population 6 months postoperatively. As a result of the ostomy, the patient may experience poorer health status or be aware of the limitations related to taking on physical roles, such as manual labor, physical activities that involve sweating and movements that increase the risk of the ostomy pouch becoming loose, or complications such as parastomal hernias.
Significantly poorer general health and vitality domains compared to the control group scores are more difficult to explain. Ito et al38 addressed lower scores in the physical, social, and role-emotional functioning in their study; these findings may be explained by the physical burden caused by the surgery and the uncertainty that patients perceive in trying to integrate ostomy-related self-care skills into their daily activities. The persistently lower HRQoL scores in the ostomy patients who participated in this study were also consistent with findings of other studies.19,21 No significant difference was found in overall QoL levels between ostomy patients and the healthy control group, which was in contrast to the differences in HRQoL scores. This difference may reflect the concept that it is possible to be satisfied with life in general and at the same time report problems with specific aspects of HRQoL associated with living with a stoma.
The adjustment process to life with an ostomy takes time. The OAS, used several times following surgery, may be useful both directly in the clinic and as an evaluation measure used by nurses and in follow-up care. Using the OAS scale as a supplement in the patient consultation may be a starting point for the discussion between the patient and the clinician in the areas that the patient experiences as most challenging. By using the OAS in measuring adjustment and as a predictor for QoL in ostomy patients, care and follow-up plans for ostomy patients can be evaluated and developed. A valid instrument for assessment is needed. ET therapists and other health care providers should be aware that some domains of HRQoL in ostomy patients may be significantly lower than the norm population, even many years after the operation. This knowledge may help clinicians balance the information they give to patients and may help the patient have realistic expectations of life with an ostomy.
The study design was cross-sectional; as such, OAS and QoL outcomes were simultaneously assessed, and causal interferences cannot be made. Most participants were older than 60 years; therefore it is unknown how a younger population would have scored. Also, only 26 (16%) participants had a urostomy. Finally, 26% of those invited did not participate in the study, so selection bias is possible.
The degree of ostomy-specific adjustment appears to be an important predictor for HRQoL and overall QoL in this group of Norwegian ostomy patients. The OAS measurement tool can be used to evaluate patient adjustment to the ostomy and their QoL and supplement clinical consultation. The results of this study indicate ostomy patients have slightly lower SF-36 scores in physical role functioning, general health, vitality, and MCS levels than the normal population, but the same overall QoL. Further longitudinal studies should explore how ostomy patients adjust to life with an ostomy over time, and how follow-up plans can be further developed and individualized.
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Potential Conflicts of Interest: none disclosed
Ms. Indrebø is a enterostomal therapist, Department of Surgery, Førde Central Hospital, Førde, Norway. Dr. Natvig is a professor, Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway. Dr. Andersen is an associate professor, Department of Surgery, Førde Central Hospital; and a Faculty of Health Studies, Sogn and Fjordane University College, Førde, Norway. Please address correspondence to: Kirsten Lerum Indrebø, MSc, Førde Sentralsjukehus, Kirurgisk, Avdeling, Svanehaugvegen 2 Førde 6814, Norway; email: Kirsten.firstname.lastname@example.org.