Feasibility and Efficacy of Internet-delivered CBT for Insomnia in a National Cohort of Danish Breast Cancer Survivors

NCT ID: NCT02444026

Last Updated: 2015-05-14

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

UNKNOWN

Clinical Phase

NA

Total Enrollment

225 participants

Study Classification

INTERVENTIONAL

Study Start Date

2014-12-31

Study Completion Date

2015-12-31

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

The aim is, in a randomized controlled trial, to test the feasibility and evaluate the efficacy of an internet-based treatment for insomnia, previously tested in a group of 28 US cancer patients, in a large sample of Danish breast cancer survivors who are experiencing significant sleep problems 0-3 years after treatment. The investigators aim to test the following hypotheses: That a group receiving Internet-delivered cognitive-behavioral therapy (CCBT) for insomnia (CCBT-I) will experience reduced sleep latency, more hours of sleep, fewer awakenings during the night, improved sleep efficiency, increased subjective sleep quality, and improved quality of life after the intervention, when compared to a waiting list control group. The investigators also aim to explore a number of possible moderators of the effect (comorbidity, depression, fear of cancer recurrence tendency to ruminate) and mediating mechanisms (changes in sleep habits and sleep-related lifestyle factors).

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

METHODS PARTICIPANTS

The participants are able, legally competent women, 18 years or older, from a national cohort of Danish women treated for primary breast cancer between 1st of June 2011 and 1st of Juli 2014:

Inclusion criteria: 1) Reported moderate-to-severe sleep disturbances, defined as a score\> 5 on the Pittsburgh Sleep Quality Index (PSQI) (32;33) (see below), and 2) are found to be disease free. Furthermore, participants 3) are required to have access to the Internet.

Exclusion criteria: 1) Recurrence of breast cancer, 2) a second cancer, 3) and other serious physical or psychological comorbidity (e.g. depression, cardiovascular disease, and COPD), 4) shift work schedule, 5) other sleep disorders (sleep apnea, narcolepsy).

PROCEDURE INFORMATION AND REQUEST TO PARTICIPATE Women who fulfill the inclusion criteria and indicate an interest in receiving further information receive an information folder by post informing.

BASELINE MEASURES:

The baseline questionnaires contains questions about sleep quality, fatigue, depression, anxiety, quality of life, sleep habits and sleep-relevant lifestyles, together with use of health care services, sleep medication, and use of alternative medicine with the aim of treating sleep problems.

INTERVENTION:

The intervention program is designed to be completed in 6 weeks. To ensure that all participants have opportunity to complete the program they are granted access to the program for nine weeks .

POST-INTERVENTION:

After the intervention, participants in both groups are asked to complete a post-intervention questionnaire package and then to fill in the sleep diary for a 2-week period.

FOLLOW-UP:

After an additional 4 weeks both groups complete two sleep questionnaires (PSQI and the insomnia severity index) after which the waiting list group is offered the intervention.

INTERVENTION The Internet intervention offered is the SHUT-i program (Sleep Healthy Using The Internet), which is based on the existing consensus concerning non-pharmacological treatment of insomnia and builds on previous validated CBT's for insomnia (CBT -I) (34).

CONTROL GROUP Participants randomly assigned to the control condition are told that for practical reasons, they have to wait 15 weeks before partaking in the intervention.

PRIMARY ENDPOINTS A) Sleep diary (bedtime, sleep onset latency (SOL), number of awakenings, total length of awakenings, wake time, arising time, daytime naps, rating of soundness of previous night's sleep, rating of refreshed feeling upon morning awakening, and information about sleep aids : medication and/or alcohol use).

B) The Pittsburgh Sleep Quality Index (PSQI) (33). C) The Insomnia Severity Index (ISI) (39).

NUMBER OF PARTICIPANTS The combined effects found in the meta-analysis of published randomized trials of Internet-based treatment for insomnia (30) are: sleep quality (d=0.41), sleep efficiency (d=0.40), number of awakenings (d=-0.45), sleep onset latency (d=-0.55), total minutes slept (d=.22), time spent in bed (d=.25). If the investigators aim to detect an effect corresponding to an average of the effects above (d = 0.38) with 80% statistical power, at least 2 x 109 participants are required.

ETHICAL CONSIDERATIONS The investigators will adhere to the general ethical guidelines for human trials. All participants receive oral and written information about the project. They are informed that they can withdraw at any time from the study with no consequence for their current or future treatment. Participants are advised to continue any medical treatment for insomnia, and to consult a doctor before changing medical regimen.

PRIVACY AND DATA SECURITY The SHUT-I program stores any personal information in a separate one-way system that cannot be accessed from the Internet but only locally by the SHUT-i administrators. Connections between personal information and other data are encrypted. Data is stored physically on servers in locked facilities, in the United States.

ADVERSE EFFECTS, INCONVENIENCES, BENEFITS, AND RISKS The investigators do not expect Internet-based cognitive behavioral therapy to be associated with any adverse health effects or risks as no adverse effects has been reported for conventional CBT for insomnia.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Insomnia

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Allocation Method

RANDOMIZED

Intervention Model

SINGLE_GROUP

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

iCBT for Insomnia

The Internet intervention offered is the SHUT-i program (Sleep Healthy Using The Internet), which is based on the existing consensus concerning non-pharmacological treatment of insomnia and builds on previous validated CBT's for insomnia (CBT -I)

Group Type EXPERIMENTAL

iCBT for Insomnia

Intervention Type BEHAVIORAL

Internet-delivered Cognitive Behavioural Therapy for Insomnia

Control

The control group will be offered the intervention AFTER the study

Group Type NO_INTERVENTION

No interventions assigned to this group

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

iCBT for Insomnia

Internet-delivered Cognitive Behavioural Therapy for Insomnia

Intervention Type BEHAVIORAL

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

* Reported moderate-to-severe sleep disturbances, defined as a score\> 5 on the Pittsburgh Sleep Quality Index (PSQI).
* Disease free.
* Access to the Internet.

Exclusion Criteria

* Recurrence of breast cancer
* A second cancer
* Other serious physical or psychological comorbidity (e.g. depression, cardiovascular disease, and COPD)
* Night work schedule
* Other sleep disorders (sleep apnea, narcolepsy) .
Minimum Eligible Age

18 Years

Maximum Eligible Age

75 Years

Eligible Sex

FEMALE

Accepts Healthy Volunteers

Yes

Sponsors

Meet the organizations funding or collaborating on the study and learn about their roles.

Danish Breast Cancer Cooperative Group

OTHER

Sponsor Role collaborator

University of Aarhus

OTHER

Sponsor Role lead

Responsible Party

Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.

Responsibility Role SPONSOR

Principal Investigators

Learn about the lead researchers overseeing the trial and their institutional affiliations.

Robert Zachariae, MDSci

Role: STUDY_DIRECTOR

Unit for Psychooncology and Health Psychology Dept. of Oncology, Aarhus University Hospital and Dept of Psychology and Behavioural Science, Aarhus University

Locations

Explore where the study is taking place and check the recruitment status at each participating site.

Unit for Psychooncology and Health Psychology, Dept. of Oncology, Aarhus University Hospital and Dept of Psychology and Behavioural Science, Aarhus University

Aarhus, Denmark, Denmark

Site Status RECRUITING

Countries

Review the countries where the study has at least one active or historical site.

Denmark

Central Contacts

Reach out to these primary contacts for questions about participation or study logistics.

Robert Zachariae, MDSci

Role: CONTACT

+45 871 65878

Jesper Dahlgaard, PhD

Role: CONTACT

+45 8716 5494 / +45 23254157

Facility Contacts

Find local site contact details for specific facilities participating in the trial.

Robert Zachariae, DMSci

Role: primary

+45 871 65878

Jesper Dahlgaard, PhD

Role: backup

+45 8716 5494 / +45 23254157

References

Explore related publications, articles, or registry entries linked to this study.

American Psychiatric Asssociation. Diagnostic and Statistical Manual of Mental Disor ders. Washington, DC: American Psychiatric Association; 2000.

Reference Type BACKGROUND

Ohayon MM. Epidemiology of insomnia: what we know and what we still need to learn. Sleep Med Rev. 2002 Apr;6(2):97-111. doi: 10.1053/smrv.2002.0186.

Reference Type BACKGROUND
PMID: 12531146 (View on PubMed)

Buysse DJ. Insomnia state of the science: an evolutionary, evidence-based assessment. Sleep. 2005 Sep;28(9):1045-6. No abstract available.

Reference Type BACKGROUND
PMID: 16268371 (View on PubMed)

Roth T. Insomnia: definition, prevalence, etiology, and consequences. J Clin Sleep Med. 2007 Aug 15;3(5 Suppl):S7-10. No abstract available.

Reference Type BACKGROUND
PMID: 17824495 (View on PubMed)

Fiorentino L, Ancoli-Israel S. Sleep dysfunction in patients with cancer. Curr Treat Options Neurol. 2007 Sep;9(5):337-46.

Reference Type BACKGROUND
PMID: 17716597 (View on PubMed)

Savard J, Ivers H, Villa J, Caplette-Gingras A, Morin CM. Natural course of insomnia comorbid with cancer: an 18-month longitudinal study. J Clin Oncol. 2011 Sep 10;29(26):3580-6. doi: 10.1200/JCO.2010.33.2247. Epub 2011 Aug 8.

Reference Type BACKGROUND
PMID: 21825267 (View on PubMed)

Price MA, Zachariae R, Butow PN, deFazio A, Chauhan D, Espie CA, Friedlander M, Webb PM; Australian Ovarian Cancer Study Group; Australian Ovarian Cancer Study - Quality of Life Study Investigators. Prevalence and predictors of insomnia in women with invasive ovarian cancer: anxiety a major factor. Eur J Cancer. 2009 Dec;45(18):3262-70. doi: 10.1016/j.ejca.2009.05.030. Epub 2009 Jun 18.

Reference Type BACKGROUND
PMID: 19540748 (View on PubMed)

Colagiuri B, Christensen S, Jensen AB, Price MA, Butow PN, Zachariae R. Prevalence and predictors of sleep difficulty in a national cohort of women with primary breast cancer three to four months postsurgery. J Pain Symptom Manage. 2011 Nov;42(5):710-20. doi: 10.1016/j.jpainsymman.2011.02.012. Epub 2011 May 26.

Reference Type BACKGROUND
PMID: 21620648 (View on PubMed)

Hall M, Baum A, Buysse DJ, Prigerson HG, Kupfer DJ, Reynolds CF 3rd. Sleep as a mediator of the stress-immune relationship. Psychosom Med. 1998 Jan-Feb;60(1):48-51. doi: 10.1097/00006842-199801000-00011.

Reference Type BACKGROUND
PMID: 9492239 (View on PubMed)

Irwin M. Effects of sleep and sleep loss on immunity and cytokines. Brain Behav Immun. 2002 Oct;16(5):503-12. doi: 10.1016/s0889-1591(02)00003-x.

Reference Type BACKGROUND
PMID: 12401464 (View on PubMed)

Baron KG, Reid KJ, Kern AS, Zee PC. Role of sleep timing in caloric intake and BMI. Obesity (Silver Spring). 2011 Jul;19(7):1374-81. doi: 10.1038/oby.2011.100. Epub 2011 Apr 28.

Reference Type BACKGROUND
PMID: 21527892 (View on PubMed)

Hairston KG, Bryer-Ash M, Norris JM, Haffner S, Bowden DW, Wagenknecht LE. Sleep duration and five-year abdominal fat accumulation in a minority cohort: the IRAS family study. Sleep. 2010 Mar;33(3):289-95. doi: 10.1093/sleep/33.3.289.

Reference Type BACKGROUND
PMID: 20337186 (View on PubMed)

Vgontzas AN, Bixler EO. Short sleep and obesity: are poor sleep, chronic stress, and unhealthy behaviors the link? Sleep. 2008 Sep;31(9):1203. No abstract available.

Reference Type BACKGROUND
PMID: 18788643 (View on PubMed)

Cappuccio FP, D'Elia L, Strazzullo P, Miller MA. Sleep duration and all-cause mortality: a systematic review and meta-analysis of prospective studies. Sleep. 2010 May;33(5):585-92. doi: 10.1093/sleep/33.5.585.

Reference Type BACKGROUND
PMID: 20469800 (View on PubMed)

Dew MA, Hoch CC, Buysse DJ, Monk TH, Begley AE, Houck PR, Hall M, Kupfer DJ, Reynolds CF 3rd. Healthy older adults' sleep predicts all-cause mortality at 4 to 19 years of follow-up. Psychosom Med. 2003 Jan-Feb;65(1):63-73. doi: 10.1097/01.psy.0000039756.23250.7c.

Reference Type BACKGROUND
PMID: 12554816 (View on PubMed)

Sleep complaints: Whenever possible, avoid the use of sleeping pills. Prescrire Int. 2008 Oct;17(97):206-12.

Reference Type BACKGROUND
PMID: 19536941 (View on PubMed)

Belleville G. Mortality hazard associated with anxiolytic and hypnotic drug use in the National Population Health Survey. Can J Psychiatry. 2010 Sep;55(9):558-67. doi: 10.1177/070674371005500904.

Reference Type BACKGROUND
PMID: 20840803 (View on PubMed)

Moore TA, Berger AM, Dizona P. Sleep aid use during and following breast cancer adjuvant chemotherapy. Psychooncology. 2011 Mar;20(3):321-5. doi: 10.1002/pon.1756.

Reference Type BACKGROUND
PMID: 20878849 (View on PubMed)

van Straten A, Cuijpers P. Self-help therapy for insomnia: a meta-analysis. Sleep Med Rev. 2009 Feb;13(1):61-71. doi: 10.1016/j.smrv.2008.04.006. Epub 2008 Oct 26.

Reference Type BACKGROUND
PMID: 18952469 (View on PubMed)

de Niet G, Tiemens B, Lendemeijer B, Hutschemaekers G. Music-assisted relaxation to improve sleep quality: meta-analysis. J Adv Nurs. 2009 Jul;65(7):1356-64. doi: 10.1111/j.1365-2648.2009.04982.x. Epub 2009 Apr 28.

Reference Type BACKGROUND
PMID: 19456998 (View on PubMed)

Irwin MR, Cole JC, Nicassio PM. Comparative meta-analysis of behavioral interventions for insomnia and their efficacy in middle-aged adults and in older adults 55+ years of age. Health Psychol. 2006 Jan;25(1):3-14. doi: 10.1037/0278-6133.25.1.3.

Reference Type BACKGROUND
PMID: 16448292 (View on PubMed)

Smith MT, Perlis ML, Park A, Smith MS, Pennington J, Giles DE, Buysse DJ. Comparative meta-analysis of pharmacotherapy and behavior therapy for persistent insomnia. Am J Psychiatry. 2002 Jan;159(1):5-11. doi: 10.1176/appi.ajp.159.1.5.

Reference Type BACKGROUND
PMID: 11772681 (View on PubMed)

Morin CM, Culbert JP, Schwartz SM. Nonpharmacological interventions for insomnia: a meta-analysis of treatment efficacy. Am J Psychiatry. 1994 Aug;151(8):1172-80. doi: 10.1176/ajp.151.8.1172.

Reference Type BACKGROUND
PMID: 8037252 (View on PubMed)

Ritterband LM, Bailey ET, Thorndike FP, Lord HR, Farrell-Carnahan L, Baum LD. Psychooncology 2011 Apr 29.

Reference Type BACKGROUND

Ritterband LM, Thorndike FP, Gonder-Frederick LA, Magee JC, Bailey ET, Saylor DK, Morin CM. Efficacy of an Internet-based behavioral intervention for adults with insomnia. Arch Gen Psychiatry. 2009 Jul;66(7):692-8. doi: 10.1001/archgenpsychiatry.2009.66.

Reference Type BACKGROUND
PMID: 19581560 (View on PubMed)

Vincent N, Lewycky S. Logging on for better sleep: RCT of the effectiveness of online treatment for insomnia. Sleep. 2009 Jun;32(6):807-15. doi: 10.1093/sleep/32.6.807.

Reference Type BACKGROUND
PMID: 19544758 (View on PubMed)

Suzuki E, Tsuchiya M, Hirokawa K, Taniguchi T, Mitsuhashi T, Kawakami N. Evaluation of an internet-based self-help program for better quality of sleep among Japanese workers: a randomized controlled trial. J Occup Health. 2008;50(5):387-99. doi: 10.1539/joh.l7154. Epub 2008 Aug 19.

Reference Type BACKGROUND
PMID: 18716392 (View on PubMed)

Strom L, Pettersson R, Andersson G. Internet-based treatment for insomnia: a controlled evaluation. J Consult Clin Psychol. 2004 Feb;72(1):113-20. doi: 10.1037/0022-006X.72.1.113.

Reference Type BACKGROUND
PMID: 14756620 (View on PubMed)

Riley WT, Mihm P, Behar A, Morin CM. A computer device to deliver behavioral interventions for insomnia. Behav Sleep Med. 2010;8(1):2-15. doi: 10.1080/15402000903425314.

Reference Type BACKGROUND
PMID: 20043245 (View on PubMed)

Cheng SK, Dizon J. Computerised cognitive behavioural therapy for insomnia: a systematic review and meta-analysis. Psychother Psychosom. 2012;81(4):206-16. doi: 10.1159/000335379. Epub 2012 May 11.

Reference Type BACKGROUND
PMID: 22585048 (View on PubMed)

Espie CA, Kyle SD, Williams C, Ong JC, Douglas NJ, Hames P, Brown JS. A randomized, placebo-controlled trial of online cognitive behavioral therapy for chronic insomnia disorder delivered via an automated media-rich web application. Sleep. 2012 Jun 1;35(6):769-81. doi: 10.5665/sleep.1872.

Reference Type BACKGROUND
PMID: 22654196 (View on PubMed)

Beck SL, Schwartz AL, Towsley G, Dudley W, Barsevick A. Psychometric evaluation of the Pittsburgh Sleep Quality Index in cancer patients. J Pain Symptom Manage. 2004 Feb;27(2):140-8. doi: 10.1016/j.jpainsymman.2003.12.002.

Reference Type BACKGROUND
PMID: 15157038 (View on PubMed)

Buysse DJ, Reynolds CF 3rd, Monk TH, Berman SR, Kupfer DJ. The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research. Psychiatry Res. 1989 May;28(2):193-213. doi: 10.1016/0165-1781(89)90047-4.

Reference Type BACKGROUND
PMID: 2748771 (View on PubMed)

NIH State-of-the-Science Conference Statement on manifestations and management of chronic insomnia in adults. NIH Consens State Sci Statements. 2005 Jun 13-15;22(2):1-30.

Reference Type BACKGROUND
PMID: 17308547 (View on PubMed)

Thorndike FP, Saylor DK, Bailey ET, Gonder-Frederick L, Morin CM, Ritterband LM. Development and Perceived Utility and Impact of an Internet Intervention for Insomnia. E J Appl Psychol. 2008;4(2):32-42. doi: 10.7790/ejap.v4i2.133.

Reference Type BACKGROUND
PMID: 20953264 (View on PubMed)

Buysse DJ, Ancoli-Israel S, Edinger JD, Lichstein KL, Morin CM. Recommendations for a standard research assessment of insomnia. Sleep. 2006 Sep;29(9):1155-73. doi: 10.1093/sleep/29.9.1155.

Reference Type BACKGROUND
PMID: 17040003 (View on PubMed)

Backhaus J, Junghanns K, Broocks A, Riemann D, Hohagen F. Test-retest reliability and validity of the Pittsburgh Sleep Quality Index in primary insomnia. J Psychosom Res. 2002 Sep;53(3):737-40. doi: 10.1016/s0022-3999(02)00330-6.

Reference Type BACKGROUND
PMID: 12217446 (View on PubMed)

Thomsen DK, Mehlsen MY, Christensen S, Zachariae Rt. Pers Individ Diff 2003;34:1293-301.

Reference Type BACKGROUND

Morin CM. Insomnia: psychological assessment and management. New York: Guilford Press; 1993.

Reference Type BACKGROUND

Bastien CH, Vallieres A, Morin CM. Validation of the Insomnia Severity Index as an outcome measure for insomnia research. Sleep Med. 2001 Jul;2(4):297-307. doi: 10.1016/s1389-9457(00)00065-4.

Reference Type BACKGROUND
PMID: 11438246 (View on PubMed)

Thorndike FP, Ritterband LM, Saylor DK, Magee JC, Gonder-Frederick LA, Morin CM. Validation of the insomnia severity index as a web-based measure. Behav Sleep Med. 2011;9(4):216-23. doi: 10.1080/15402002.2011.606766.

Reference Type BACKGROUND
PMID: 22003975 (View on PubMed)

Savard MH, Savard J, Simard S, Ivers H. Empirical validation of the Insomnia Severity Index in cancer patients. Psychooncology. 2005 Jun;14(6):429-41. doi: 10.1002/pon.860.

Reference Type BACKGROUND
PMID: 15376284 (View on PubMed)

Yellen SB, Cella DF, Webster K, Blendowski C, Kaplan E. Measuring fatigue and other anemia-related symptoms with the Functional Assessment of Cancer Therapy (FACT) measurement system. J Pain Symptom Manage. 1997 Feb;13(2):63-74. doi: 10.1016/s0885-3924(96)00274-6.

Reference Type BACKGROUND
PMID: 9095563 (View on PubMed)

Beck AT, Steer RA, Brown GK. Manual: Beck Depression Inventory. 2 ed. San Antonio, TX: The Psychological Corporation. Hartcourt & Brace.; 1996.

Reference Type BACKGROUND

Christensen S, Zachariae R, Jensen AB, Vaeth M, Moller S, Ravnsbaek J, von der Maase H. Prevalence and risk of depressive symptoms 3-4 months post-surgery in a nationwide cohort study of Danish women treated for early stage breast-cancer. Breast Cancer Res Treat. 2009 Jan;113(2):339-55. doi: 10.1007/s10549-008-9920-9. Epub 2008 Feb 16.

Reference Type BACKGROUND
PMID: 18278553 (View on PubMed)

Spielberger CD. Psychological Assessment Resources Odessa FA 1988 1988.

Reference Type BACKGROUND

Zachariae R, Melchiorsen H, Frobert O, Bjerring P, Bagger JP. Experimental pain and psychologic status of patients with chest pain with normal coronary arteries or ischemic heart disease. Am Heart J. 2001 Jul;142(1):63-71. doi: 10.1067/mhj.2001.115794.

Reference Type BACKGROUND
PMID: 11431658 (View on PubMed)

Gandek B, Ware JE, Aaronson NK, Apolone G, Bjorner JB, Brazier JE, Bullinger M, Kaasa S, Leplege A, Prieto L, Sullivan M. Cross-validation of item selection and scoring for the SF-12 Health Survey in nine countries: results from the IQOLA Project. International Quality of Life Assessment. J Clin Epidemiol. 1998 Nov;51(11):1171-8. doi: 10.1016/s0895-4356(98)00109-7.

Reference Type BACKGROUND
PMID: 9817135 (View on PubMed)

Bjørner JB, Damsgaard MT, Watt T, Bech P, Rasmussen NK, Kristensen TS, et al. Copenhagen: Lif; 1997.

Reference Type BACKGROUND

Broadbent DE, Cooper PF, FitzGerald P, Parkes KR. The Cognitive Failures Questionnaire (CFQ) and its correlates. Br J Clin Psychol. 1982 Feb;21(1):1-16. doi: 10.1111/j.2044-8260.1982.tb01421.x.

Reference Type BACKGROUND
PMID: 7126941 (View on PubMed)

Katz JN, Chang LC, Sangha O, Fossel AH, Bates DW. Can comorbidity be measured by questionnaire rather than medical record review? Med Care. 1996 Jan;34(1):73-84. doi: 10.1097/00005650-199601000-00006.

Reference Type BACKGROUND
PMID: 8551813 (View on PubMed)

Charlson M, Szatrowski TP, Peterson J, Gold J. Validation of a combined comorbidity index. J Clin Epidemiol. 1994 Nov;47(11):1245-51. doi: 10.1016/0895-4356(94)90129-5.

Reference Type BACKGROUND
PMID: 7722560 (View on PubMed)

Roger D, Najarian B. Pers Indiv Diff 1989;10(8):845-53.

Reference Type BACKGROUND

Weiss, D.S. The Impact of Event Scale-Revised. In J.P. Wilson, & T.M. Keane (Eds.), Assessing psychological trauma and PTSD: A practitioner'shandbook (2nd ed., pp. 168-189).2004. New York: Guilford Press.

Reference Type BACKGROUND

Kubany ES, Haynes SN, Leisen MB, Owens JA, Kaplan AS, Watson SB, Burns K. Development and preliminary validation of a brief broad-spectrum measure of trauma exposure: the Traumatic Life Events Questionnaire. Psychol Assess. 2000 Jun;12(2):210-24. doi: 10.1037//1040-3590.12.2.210.

Reference Type BACKGROUND
PMID: 10887767 (View on PubMed)

O'Connor M, Christensen S, Jensen AB, Moller S, Zachariae R. How traumatic is breast cancer? Post-traumatic stress symptoms (PTSS) and risk factors for severe PTSS at 3 and 15 months after surgery in a nationwide cohort of Danish women treated for primary breast cancer. Br J Cancer. 2011 Feb 1;104(3):419-26. doi: 10.1038/sj.bjc.6606073. Epub 2011 Jan 11.

Reference Type BACKGROUND
PMID: 21224851 (View on PubMed)

Pedersen CG, Christensen S, Jensen AB, Zachariae R. Prevalence, socio-demographic and clinical predictors of post-diagnostic utilisation of different types of complementary and alternative medicine (CAM) in a nationwide cohort of Danish women treated for primary breast cancer. Eur J Cancer. 2009 Dec;45(18):3172-81. doi: 10.1016/j.ejca.2009.09.005. Epub 2009 Oct 5.

Reference Type BACKGROUND
PMID: 19811905 (View on PubMed)

Baron RM, Kenny DA. The moderator-mediator variable distinction in social psychological research: conceptual, strategic, and statistical considerations. J Pers Soc Psychol. 1986 Dec;51(6):1173-82. doi: 10.1037//0022-3514.51.6.1173.

Reference Type BACKGROUND
PMID: 3806354 (View on PubMed)

Kenny DA, Kashy DA, Bolger N. Data analysis in social psychology. In: Gilbert D, Fiske S,Lindzey G, editors. The handbook of social psychology. 4 ed. Boston,MA: McGraw-Hill; 1998. p. 233-65.

Reference Type BACKGROUND

MacKinnon DP, Lockwood CM, Hoffman JM, West SG, Sheets V. A comparison of methods to test mediation and other intervening variable effects. Psychol Methods. 2002 Mar;7(1):83-104. doi: 10.1037/1082-989x.7.1.83.

Reference Type BACKGROUND
PMID: 11928892 (View on PubMed)

Sobel ME. Asymptotic intervals for indirect effects in structural equation models. In: Leinhart S, editor. Sociological methodology.San Francisco: Jossey-Bass; 1982. p. 290-312.

Reference Type BACKGROUND

Muller D, Judd CM, Yzerbyt VY. When moderation is mediated and mediation is moderated. J Pers Soc Psychol. 2005 Dec;89(6):852-63. doi: 10.1037/0022-3514.89.6.852.

Reference Type BACKGROUND
PMID: 16393020 (View on PubMed)

Danmarks Statistik (Statistics Denmark). Befolkningens brug af internet (Internet use in the Danish population). Copenhagen: Danmarks Statistik (Statistics Denmark); 2011.

Reference Type BACKGROUND

Jensen-Johansen M, Christensen S, Valdimarsdottir H, Zakowski S, Bovbjerg DH, Jensen AB, et al. Unpublished manuscript 2010.

Reference Type BACKGROUND

Uniform requirements for manuscripts submitted to biomedical journals. International Committee of Medical Journal Editors. Ann Intern Med. 1997 Jan 1;126(1):36-47. doi: 10.7326/0003-4819-126-1-199701010-00006. No abstract available.

Reference Type BACKGROUND
PMID: 8992922 (View on PubMed)

Moher D, Hopewell S, Schulz KF, Montori V, Gotzsche PC, Devereaux PJ, Elbourne D, Egger M, Altman DG. CONSORT 2010 explanation and elaboration: updated guidelines for reporting parallel group randomised trials. BMJ. 2010 Mar 23;340:c869. doi: 10.1136/bmj.c869. No abstract available.

Reference Type BACKGROUND
PMID: 20332511 (View on PubMed)

Other Identifiers

Review additional registry numbers or institutional identifiers associated with this trial.

M-2012-553-12

Identifier Type: -

Identifier Source: org_study_id

More Related Trials

Additional clinical trials that may be relevant based on similarity analysis.