ABSTRACT
This study conducted to evaluate the effect of white spectrum light on sleep and life quality in breast cancer patients who received radiotherapy.
The sample of this randomized controlled study consisted of patients with low sleep quality who did not report pain, fatigue, depression and anxiety. Research data were collected using by Individual Identification Feature Form, Sleep and Light Application Follow up Form, Beck Depression scale, Beck Anxiety scale, The European Organization for Research and Treatment of Cancer Quality-of-Life Questionnaire (EORTC QLQ) C-30, Pittsburg Sleep Quality index (PSQI) and Numerical Pain Rating scale. Patients who met the sampling selection criteria (n=23) were randomized in to the intervention and control groups. The control group patients were rested while the intervention group was applied to 10.000 lux white light/30 min/day in a week. Sleep and life quality of both groups of patients were assessed twice as before the radiotherapy and on the eighth day of radiotherapy.
The mean PSQI score of both groups was greater than five points at the first assessment performed before radiotherapy, on the eighth day of radiotherapy it was below five points. In the second assessment intervention group’s PSQI mean score was lower compared with the control group [(intervention group=5.0±2.32, control group=6.50±3.26), (U=85.000, p=0.260)]. In the study, while the EORTC QLQ C-30 functional subscale score increased in the second assessment according to the first assessment in the intervention and control groups, the symptom subscale score decreased and there was no change in the global health score.
In this study, it was determined that white light does not affect on sleep and quality of life in patients with breast cancer who received radiotherapy.
Keywords: Radiotherapy, sleep quality, quality of life, bright white light
Introduction
Study Design
Study Setting and Population
This study was conducted in the Radiation Oncology Center of a Hospital in Eskişehir between November 1, 2016 and September 30, 2017. The research universe consisted of breast cancer patients who received radiotherapy in the radiation oncology service during the research period. The study sample included patients who met the inclusion criteria within the study universe.
Inclusion criteria: This criterion included patients between 18 and 74 years of age who could read and write, were conscious, did no night shift work, and had bad sleep quality [the Pittsburg Sleep Quality index (PSQI) score was more than 5]. These patients did not report any pain (0 points on the Numerical Pain Assessment scale), fatigue, depression (less than 13 points on the Beck Depression inventory), and anxiety (less than 8 points from the Beck Anxiety inventory). Moreover, these patients did not perceive light, had natural/contact lens and did not any change their medication protocol within the last three months.
Outcome Measures
Research data was collected at two-time points (on the first day of the radiotherapy and the eighth day of the radiotherapy) using observation, interview, and assessment methods. The personal introduction form, sleep, and light monitoring form, Beck Depression inventory, Beck Anxiety inventory, The European Organization for Research and Treatment of Cancer Quality-of-Life Questionnaire-30 (EORTC QLQ C-30), the PSQI, the Numeric Pain Assessment scale, light source, and a lux meter were used to collect data.
Personal introduction form: This form was prepared based on literature, which includes patients’ socio-demographic characteristics, information regarding disease and its treatment (3,5,6,14,15,17).
Sleep and light monitoring form: This form was developed based on previous studies and included questions regarding the information on the features of the patients’ bedrooms (temperature, light, sound) and the side effects of the light (having dry, itchy and burning eyes, redness on face and arms, skin sensitivity, nervousness, headache, nausea, and vomiting, body temperature) (6,18).
Pittsburg Sleep Quality index: This index was developed in 1988. The reliability and validity study of the scale in the Turkish population was carried out by Ağargün et al. (19) in 1996. The scale consists of seven components. Each item in the scale was scored between 0 and 3. The range of overall PSQI score varied between 0 and 21. Sleep quality is evaluated as poor in those with an overall score of more than 5 and fine in those with an overall score of 5 or lower.
The European Organization for Research and Treatment of Cancer Quality-of-Life Questionnaire C-30: The questionnaire developed by EORTC, and the EORTC QLQ C-30 Version 3.0 is a quality of life questionnaire commonly used for cancer patients all over the world. An item analysis was carried out to determine the relationship among the scale items. A strong relationship was found with a Cronbach alpha value of r=0.9014. EORTC QLQ C-30 Quality-of-Life Questionnaire contains 30 questions and three headings like general well-being, functional difficulties, and symptom control. The questions, 28 out of 30, were designed with a 4-point Likert scale and answers of the questions are made up of none: 1, very less: 2, fairly: 3, and much: 4. By the 29th and 30th questions of the scale, the patients were asked to assess their well-being and general quality of life, respectively with a 7-point Likert scale (1: too bad and 7: perfect) questions 29 and 30, inquired about general well-being. Higher scores in functional and general well-being subscales and a lower score in symptoms are associated with higher quality of life (20).
The Numeric Pain Assessment scale: This is a self-assessment scale for patients to assess the severity of pain. The numeric rating scale utilizes a linear scale from 0-10, with 0 representing “no pain” and ten being indicative of “pain as bad as you can imagine” (21).
The Beck Anxiety inventory: It was created in 1988 to assess the severity of anxiety in individuals. The Turkish reliability and validity studies were performed as described by Ulusoy et al. (22) in 1998 using a self-rated anxiety scale also asking for physiological symptoms. It is a 21-item self-report instrument that measures symptoms of anxiety using a 4-point Likert-type scale (0-3). The test has a maximum of 63 points. The total score of 0-7 is considered as a minimal level of anxiety, 8-15 is mild anxiety, 16-25 is moderate anxiety, and 26-63 is severe anxiety. Higher scores reflect higher levels of anxiety.
The Beck Depression inventory: It was developed in 1967. It is a 21 item self-report, a questionnaire, wherein the patients are asked to choose the statement that best describes their attitude towards the item. Each item had four response options, and the answers were scored on a scale value of 0 (neutral) to 3 (the most severe). The statements included in this scale were self-reports of depression patients who underwent treatment. The maximum total score was 63. A total score of 0-13 is considered minimal range (no depression), 14-24 is moderate, and 25-63 indicates severe depression. The validity and reliability study of the Turkish version of the scale was conducted by Hisli (23).
Light source: Exposure to bright white light (2000-3000 lux) for 1-2 hours is sufficient to regulate the circadian rhythm for eliminating sleep disorders and improving sleep quality (14,15,24,25). A high lumen bright white light box with 220v 85-105w was used in the patients’ environment.
Lux meter: It is a portable, practical device used to measure the amount of light for a 10.000 lux standard light therapy regime for the patients.
Intervention
Statistical Analysis
Ethical Considerations
This study was approved by Eskişehir Osmangazi University Ethical Committee (approval date/number: October 25, 2016/80558721/216). After giving written and verbal information, all study subjects gave written consent. They were informed that if they did not want to continue, they can leave the study without stating a reason.
Results
Socio-demographic and clinical characteristics of the sample: All breast cancer patients (n=78) who received radiotherapy within a year were reached for the research, and 29.4% of patients (n=23) were found to have low sleep quality. All patients who had low sleep quality were female, and the mean age of the participants was 51.21±2.07 years. Of the patients, 82.6% were married, and 52.2% were primary school graduates. Regarding the income level, 78.3% of the patients expressed that their income met their expenses. Among them, 39.1% had chronic disease and 65.2% had stage 2 (Table 1). All patients in the intervention group adapted to the bright white light intervention and no side effect was observed.
Pittsburg Sleep Quality index scores of the sample: While the PSQI mean score of each group were greater than five points according to the first assessment performed before radiotherapy (PSQI; intervention=9.54±4.84, control=8.50±3.47), PSQI mean score decreased in both of groups in the second assessment (PSQI; intervention=5.0±2.32, control=6.50±3.26), (Table 2). However, the researchers found a change between the first and the second assessment values. PSQI mean score was lower in the intervention group compared with the control group in the second measurement (U=85.000, p=0.260) (Table 2).
The European Organization for Research and Treatment of Cancer Quality-of-Life Questionnaire C-30 subscale scores of the sample: It was determined that the mean score of the functional subscale of intervention and control groups be greater in the second assessment compared with the first assessment. Moreover, the mean score of symptom subscale decreased in both of groups in the second assessment while no difference was found for the mean score of global well-being (Table 2). Although no significant difference was found among the groups for the mean score of functional subscale, the symptom subscale or the global-wellbeing subscale, the mean score of the symptom subscale was higher, and the mean scores of the functional subscale and global well-being subscale were lower in the intervention group compared with the control group [Scores in the functional subscale: (First assessment: U=63.500, p=0.880); (Second assessment: U=81.500, p=0.347)], [Scores in the symptom subscale: (First assessment: U=70.500, p=0.786), (Second assessment: U=72.000, p=0.740)], [Scores in the global wellbeing subscale: (First assessment: U=62.000, p=0.833), (Second assessment: U=62.000, p=0.833)] (Table 2).
Discussion
Conclusion
This study is randomized controlled study examining the impact of light on sleep and quality of life of breast cancer patients who received radiotherapy. Research findings have limited the validity of the results obtained from the PSQI and EORTC-C30, of which the validity and reliability were conducted based on self-report of patients. The discussion section is limited as there were not many studies examining the impact of light on the quality of life of the breast cancer patients. Therefore, it is suggested that further studies should also focus on the quality of life and include a wide population of sampling group, use objective measurement devices like actigraphy to deeply analyze sleep quality and sleep disorders associated with the circadian rhythm disorders.
Ethics
Ethics Committee Approval: This study was approved by Eskişehir Osmangazi University Clinical Research Ethics Committee (approval date/number: October 25, 2016/80558721/216).
Informed Consent: After giving written and verbal information, all study subjects gave written consent.
Peer-review: Internally peer-reviewed.
Authorship Contributions
Concept: A.Ö., E.M., E.Ç., Design: A.Ö., N.K., G.B.A., Data Collection or Processing: E.Ö., Ö.K., A.Ö., E.M., Analysis or Interpretation: A.Ö., E.Ç., Literature Search: G.B.A., N.K., Writing: A.Ö., Ö.K.
Conflict of Interest: We noted as authors to you that manuscript has no all possible conflicts of interest, including financial, consultant, institutional and other relationships.
Financial Disclosure: This work was supported Scientific Research Project Unit of Eskişehir Osmangazi University, Eskişehir, Turkey (grant number: 2015-875).
