Abstract
Many physical diseases have been reported to be associated with psychosocial factors. In these diseases, assessment relies mainly on subjective symptoms in natural settings. Therefore, it is important to assess symptoms and/or relationships between psychosocial factors and symptoms in natural settings. Symptoms are usually assessed by self-report when patients visit their doctors. However, self-report by recall has an intrinsic problem; "recall bias". Recently, ecological momentary assessment (EMA) has been proposed as a reliable method to assess and record events and subjective symptoms as well as physiological and behavioral variables in natural settings. Although EMA is a useful method to assess stress-related diseases, it has not been fully acknowledged, especially by clinicians. Therefore, the present brief review introduces the application and future direction of EMA for the assessment and intervention for stress-related diseases.
Introduction
Many physical diseases have been reported to be associated with psychosocial factors such as irritable bowel syndrome (IBS) [1], primary headaches [2], and asthma [3]. In these diseases, assessment relies mainly on subjective symptoms in natural settings. Therefore, it is important to assess symptoms and/or relationships between psychosocial factors and symptoms in natural settings.
Symptoms are usually assessed by self-report when patients visit their doctors. Most self-reported data are collected by questionnaires or interviews that ask patients to summarize past symptoms over some period of time. For example, a pain questionnaire might ask about the intensity of last week's pain. However, self-report by recall has an intrinsic problem; "recall bias". Many research data have shown that people are not be able to accurately recall past experience, particularly experiences that are frequent, mundane, and irregular, because self-report data are affected by recall biases such as their mood states (state biases) (Table 1) [4]. In addition to the state biases, there are other recall biases affecting self-report data: (1) recency, which means that more recent events are more accessible to memory, (2) saliency, which means that salient experiences are more likely to be encoded and subsequently recalled, (3) effort after meaning, which means that people's natural and unconscious tendency is to reconstruct events so as to make them consistent with subsequent events, (4) participants' misunderstanding of questionnaire instruction sets that require them to aggregate and summarize their experience in the recent past, and (5) aggregation, which is cognitive processing that is necessary to respond to questions about the occurrence or frequency of events or about their average or typical characteristics [5]. In fact, there have been some studies that show inconsistency between recalled symptoms and momentary recorded symptoms [6-8]. Especially, previous studies indicated that variability of symptoms could affect the recall (Table 2) [7,8].
Table 1.
Recall biases affecting self-report data
| State biases |
| Recency |
| Saliencey |
| Effort after meaning |
| Misunderstanding of instruction set |
| Aggregation |
Table 2.
Consistency between recalled headache intensity and momentary headache intensity for the two subgroups of patients with tension-type headache
| low SD group | high SD group | |||
| Mean (SD) | ICC (A, 1) (95% C.I.) | Mean (SD) | ICC (A, 1) (95% C.I.) | |
| Recalled headache intensity and | 54.7 (22.5) | 59.5 (17.8) | ||
| mean headache intensity of all recordings | 41.3 (23.2)* | 0.75 (0.04, 0.93) | 33.5 (16.8)* | 0.21 (-0.11, 0.56) |
| mean headache intensity of scheduled recordings only | 41.1 (22.4)* | 0.75 (0.00, 0.93) | 29.2 (16.2)* | 0.16 (-0.09, 0.48) |
| mean headache intensity of event-contingent recordings only | 60.3 (23.0) | 0.81 (0.41, 0.95) | 66.8 (12.2) | 0.21 (-0.22, 0.60) |
| mean headache intensity of recordings when headaches were present | 44.7 (19.0)* | 0.77 (0.24, 0.92) | 40.5 (13.0)* | 0.29 (-0.11, 0.65) |
| maximal headache intensity of all recordings | 71.5 (19.0)* | 0.64 (-0.08, 0.89) | 83.0 (11.7)* | 0.23 (-0.10, 0.59) |
ICC (A, 1), intraclass correlation coefficient of absolute agreement; SD, standard deviation; C.I., confidence interval.
* P < 0.001, vs. recalled headache intensity.
Recalled headache intensity was compared with some indices of momentary headache intensity.
High SD group is a group of patients whose headache intensity was highly variable.
Ecological momentary assessment (EMA) has been proposed as a reliable method to assess and record events and subjective symptoms as well as physiological and behavioral data in natural settings [9]. Recently, Burton et al. [10] reported an excellent systematic review of electronic diaries for self-report data such as pain and symptoms. In addition, Smyth and Stone [11] made a fabulous review of EMA research in behavioral medicine showing some examples including objective data such as cortisol in healthy people and peak expiratory flow in asthma patients. However, little attention has been paid to physical activity recorded objectively in the context of EMA research, although some studies using physical activity as an EMA variable have been published. Therefore, in the present brief review, we would like to introduce EMA and its usefulness, especially physical activity data as an object variable in EMA. In addition, we would like to discuss future applications of EMA for intervention in lifestyle-related physical diseases such as obesity and diabetes mellitus.
Ecological momentary assessment (EMA)
EMA is a sampling method developed 'to assess phenomena at the moment they occur in natural settings, thus maximizing ecological validity while avoiding retrospective recall' [9]. When applying EMA to stress-related diseases such as IBS and asthma, paper-and-pencil diaries have often been used as recording devices [12,13]. However, such diaries have the disadvantage of 'faked compliance', i.e. disguise of compliance by recording data at times other than those designated even if signaling is used to remind patients of recording data [14-16].
To overcome this 'faked compliance', computerized EMA, i.e. EMA using computers as electronic diaries, has been developed. In computerized EMA, the input time is also recorded by the device in order to avoid faked compliance [17]. In addition, electronic diaries are able to issue randomly scheduled prompts to solicit data entry, thus reducing the risk that the assessment schedule may affect a natural rhythm in patients' lives [17].
Electronic diaries have been often implemented in palm-size computers [18-20] or watch-type computers (Fig. 1) [8,21] while an electronic touch-tone telephone system has been also used as a validated system [22]. The details of proposed guidelines and designing protocols for EMA are beyond the scope of the present report and have been described in previous reports [17,23,24].
Figure 1.

The watch-type computer device used in previous studies [8,20,55,57]. It is easy to manipulate the device using the joystick to lengthen or shorten the bar-like visual analogue scale and to push the enter-button to record the scale.
Analysis of EMA data
Generally, the structure of momentary data is complex. Most time-series data tend to show serial autocorrelation, which violates the assumption of independence underlying parametric statistical methods such as multivariate regression. In addition, repeated measures of analysis of variance (RM-ANOVA), a well-known technique for analyzing data collected over time, cannot be applied to the analysis of most real-time data because the assumption underlying the strict data structure required by RM-ANOVA are mostly not met, which includes equally spaced data and no missing data. In contrast, multilevel modeling is able to deal with many characteristics of momentary data collected by EMA [25]. A comprehensive step-by-step lecture for analyzing real-time data using multilevel modeling was described in a previous report by Schwartz [26].
Previous studies using EMA in stress-related diseases
Assessing self-report symptoms
There have been many studies using EMA to assess subjective symptoms in stress-related physical diseases. Most studies assess pain in pain-related physical diseases such as rheumatoid arthritis, fibromyalgia and headaches [18-20,27-39]. Fatigue has also been evaluated using EMA in many studies [21,40-45] because pain and fatigue are difficult to assess objectively. Eating disorders are also major problems to be handled, and there have been some studies using EMA to assess symptoms in patients with bulimia nervosa or with binge eating disorder in natural settings [46-54] although there have been few studies on anorexia nervosa. Recently, attempts have been made to apply EMA to other stress-related physical diseases such as IBS [55].
Assessing subjective symptoms and objective data using wearable devices
Recently, there have been some studies, but not many, using wearable devices for assessing and recording objective data as well as subjective symptoms in natural settings. Kamarck et al. [56] showed, using electronic diaries and ambulatory blood pressure monitoring, that daily psychosocial demands caused elevation of ambulatory blood pressure. Smyth et al. [57] reported the association between psychological stress and salivary cortisol secretion. Saito et al. [58] reported that chemical substances in the air caused subjective symptoms in patients with multiple chemical sensitivity using electronic diaries and wearable gas-samplers in natural settings. Affleck et al. [59] and Smyth et al. [60] reported that peak expiratory flow rate was associated with psychosocial factors in asthma patients using peak flow meters. In addition, there have been some recent studies [61-64] assessing the relationship between subjective symptoms and physical activity using actigraphy in natural settings. These previous studies using actigraphy have also successfully yielded many novel findings.
In our recent study [61], for example, watch-type wearable computers equipped with an actigraphy inside were used for recording momentary headache intensity and physical activity simultaneously (Figure 1). The results of the study showed objectively that there were significant negative associations between headache intensity and the simultaneous and subsequent activity level, and that activity level was significantly reduced at headache exacerbations (Figure 2). There have been few devices that are able to collect long-term objective data noninvasively in natural settings. Therefore, actigraphy is one of the most useful devices for EMA research at this point.
Figure 2.
Example of data for momentary headache intensity and physical activity of a patient with tension-type headache [57]. Line graph shows physical activity counts per minute. Open circle shows momentary headache intensity. Headache was exacerbated and the patient added an event-contingent recording around 19:30 (open circle). It seems that physical activity was decreased after the headache exacerbation.
Future direction
Because recent studies using actigraphy show significant findings by applying sophisticated time-series data analyses [65-68], more attention should be paid to objectively assessed and recorded data such as locomotor activity and behavior in natural settings. In addition, autonomic nervous function has been reported to be impaired in patients with psychosomatic disorders [69-71]. Therefore, in the near future, studies should be performed for longer duration, i.e. a few years [72], using wearable devices to simultaneously collect behavioral data, locomotor activity, and physiological data as well as subjective symptoms [73,74].
In addition, one future application of EMA is a tool for intervention in lifestyle-related physical diseases such as obesity and diabetes mellitus. In psychiatric diseases such as anxiety disorders, there have already been some studies [75-77] on computerized cognitive behavioral therapy (CCBT) using palm-size computers, although the efficacy of CCBT has not been confirmed. In addition, internet-based intervention has been reported to be effective in lifestyle-related diseases such as obesity [78,79] and diabetes [80]. However, there have been few studies on the effect of behavioral change programs or CCBT using palm-size computers, which could provide timely feedback or intervention in natural settings. Therefore, application of EMA technique to intervention in lifestyle-related diseases should be conducted in the near future.
Conclusion
Computerized EMA will be able to yield more fruitful findings about the relationships between psychosocial factors and stress-related diseases when wearable devices are developed to assess and record more physiological and behavioral data in natural settings.
List of abbreviations used
IBS: irritable bowel syndrome; EMA: ecological momentary assessment; CCBT: computerized cognitive behavior therapy.
Competing interests
The authors declare that they have no competing interests.
Authors' contributions
KY, YY, and AA wrote and approved the final manuscript.
Acknowledgments
Acknowledgements
This study was partly funded by a grant from the Department of the Ministry of Health, Labor, and Welfare of Japan (K.Y.).
Contributor Information
Kazuhiro Yoshiuchi, Email: kyoshiuc-tky@umin.ac.jp.
Yoshiharu Yamamoto, Email: yamamoto@p.u-tokyo.ac.jp.
Akira Akabayashi, Email: akirasan-tky@umin.ac.jp.
References
- Nicholl BI, Halder SL, Macfarlane GJ, Thompson DG, O'brien S, Musleh M, McBeth J. Psychosocial risk markers for new onset irritable bowel syndrome – Results of a large prospective population-based study. Pain. 2008;137:147–155. doi: 10.1016/j.pain.2007.08.029. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Labbe EE, Murphy L, O'Brien C. Psychosocial factors and prediction of headaches in college adults. Headache. 1997;37:1–5. doi: 10.1046/j.1526-4610.1997.3701001.x. [DOI] [PubMed] [Google Scholar]
- Wainwright NW, Surtees PG, Wareham NJ, Harrison BD. Psychosocial factors and incident asthma hospital admissions in the EPIC-Norfolk cohort study. Allergy. 2007;62:554–560. doi: 10.1111/j.1398-9995.2007.01316.x. [DOI] [PubMed] [Google Scholar]
- Bradburn NM, Rips LJ, Shevell SK. Answering autobiographical questions: the impact of memory and inference on surveys. Science. 1987;236:157–161. doi: 10.1126/science.3563494. [DOI] [PubMed] [Google Scholar]
- Hfford MR. Special methodological challenges and opportunities in ecological momentary assessment. In: Stone AA, Shiffman S, Atienza AA, Nebeling L, editor. The Science of REAL-TIME Data Capture. New York: Oxford University Press; 2007. pp. 54–75. [Google Scholar]
- Stone AA, Broderick JE, Shiffman SS, Schwartz JE. Understanding recall of weekly pain from a momentary assessment perspective: absolute agreement, between- and within-person consistency, and judged change in weekly pain. Pain. 2004;23:354–362. doi: 10.1016/j.pain.2003.09.020. [DOI] [PubMed] [Google Scholar]
- Stone AA, Schwartz JE, Broderick JE, Shiffman SS. Variability of momentary pain predicts recall of weekly pain: a consequence of the peak (or salience) memory heuristic. Pers Soc Psychol Bull. 2005;31:1340–1346. doi: 10.1177/0146167205275615. [DOI] [PubMed] [Google Scholar]
- Kikuchi H, Yoshiuchi K, Miyasaka N, Ohashi K, Yamamoto Y, Kumano H, Kuboki T, Akabayashi A. Reliability of recalled self-report on headache intensity: investigation using ecological momentary assessment technique. Cephalalgia. 2006;26:1335–1343. doi: 10.1111/j.1468-2982.2006.01221.x. [DOI] [PubMed] [Google Scholar]
- Stone AA, Shiffman S. Ecological momentary assessment (EMA) in behavioral medicine. Ann Behav Med. 1994;16:199–202. [Google Scholar]
- Burton C, Weller D, Sharpe M. Are electronic diaries useful for symptom research? A systematic review. J Psychosom Res. 2007;62:553–561. doi: 10.1016/j.jpsychores.2006.12.022. [DOI] [PubMed] [Google Scholar]
- Smyth JM, Stone AA. Ecological momentary assessment research in behavioral medicine. J Happiness Stud. 2003;4:35–52. doi: 10.1023/A:1023657221954. [DOI] [Google Scholar]
- Cain KC, Headstrom P, Jarrett ME, Motzer SA, Park H, Burr RL, Surawicz CM, Heitkemper MM. Abdominal pain impacts quality of life in women with irritable bowel syndrome. Am J Gastroenterol. 2006;101:124–132. doi: 10.1111/j.1572-0241.2006.00404.x. [DOI] [PubMed] [Google Scholar]
- Johnston SL, Blasi F, Black PN, Martin RJ, Farrell DJ, Nieman RB, TELICAST Investigators The effect of telithromycin in acute exacerbations of asthma. N Engl J Med. 2006;354:1589–1600. doi: 10.1056/NEJMoa044080. [DOI] [PubMed] [Google Scholar]
- Stone AA, Shiffman S, Schwartz JE, Broderick JE, Hufford MR. Patient non-compliance with paper diaries. Br Med J. 2002;324:1193–1194. doi: 10.1136/bmj.324.7347.1193. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Broderick JE, Schwartz JE, Shiffman S, Hufford MR, Stone AA. Signaling does not adequately improve diary compliance. Ann Behav Med. 2003;26:139–148. doi: 10.1207/S15324796ABM2602_06. [DOI] [PubMed] [Google Scholar]
- Burke LE, Sereika SM, Music E, Warziski M, Styn MA, Stone A. Using instrumented paper diaries to document self-monitoring patterns in weight loss. Contemp Clin Trials. 2008;29:182–193. doi: 10.1016/j.cct.2007.07.004. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stone AA, Shiffman S. Capturing momentary, self-report data: a proposal for reporting guidelines. Ann Behav Med. 2002;24:236–243. doi: 10.1207/S15324796ABM2403_09. [DOI] [PubMed] [Google Scholar]
- Litcher-Kelly L, Stone AA, Broderick JE, Schwartz JE. Associations among pain intensity, sensory characteristics, affective qualities, and activity limitations in patients with chronic pain: a momentary, within-person perspective. J Pain. 2004;5:433–439. doi: 10.1016/j.jpain.2004.07.005. [DOI] [PubMed] [Google Scholar]
- Turner JA, Mancl L, Aaron LA. Pain-related catastrophizing: a daily process study. Pain. 2004;110:103–111. doi: 10.1016/j.pain.2004.03.014. [DOI] [PubMed] [Google Scholar]
- Aaron LA, Turner JA, Mancl L, Brister H, Sawchuk CN. Electronic diary assessment of pain-related variables: is reactivity a problem? J Pain. 2005;6:107–115. doi: 10.1016/j.jpain.2004.11.003. [DOI] [PubMed] [Google Scholar]
- Yoshiuchi K, Cook DB, Ohashi K, Yamamoto Y, Kumano H, Kuboki T, Natelson BH. A real-time assessment of the effect of exercise in chronic fatigue syndrome. Physiol Behav. 2007;92:963–968. doi: 10.1016/j.physbeh.2007.07.001. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Camilleri M, Northcutt AR, Kong S, Dukes GE, McSorley D, Mangel AW. Efficacy and safety of alosetron in women with irritable bowel syndrome: a randomised, placebo-controlled trial. Lancet. 2000;355:1035–1040. doi: 10.1016/S0140-6736(00)02033-X. [DOI] [PubMed] [Google Scholar]
- Shiffman S. Designing protocols for ecological momentary assessment. In: Stone AA, Shiffman S, Atienza AA, Nebeling L, editor. The Science of REAL-TIME Data Capture. New York: Oxford University Press; 2007. pp. 27–53. [Google Scholar]
- Palm blad M, Tiplady B. Electronic diaries and quesitonnaires: designing used interfaces that are easy for all patients to use. Qual Life Res. 2004;13:1199–1207. doi: 10.1023/B:QURE.0000037501.92374.e1. [DOI] [PubMed] [Google Scholar]
- Schwartz JE, Stone AA. Strategies for analyzing ecological momentary assessment data. Health Psychol. 1998;17:6–16. doi: 10.1037/0278-6133.17.1.6. [DOI] [PubMed] [Google Scholar]
- Schhwartz JE. The analysis of real-time momentary data. In: Stone AA, Shiffman S, Atienza AA, Nebeling L, editor. The Science of REAL-TIME Data Capture. New York: Oxford University Press; 2007. pp. 76–113. [Google Scholar]
- Aaron LA, Mancl L, Turner JA, Sawchuk CN, Klein KM. Reasons for missing interviews in the daily electronic assessment of pain, mood, and stress. Pain. 2004;109:389–398. doi: 10.1016/j.pain.2004.02.014. [DOI] [PubMed] [Google Scholar]
- Turner JA, Mancl L, Aaron LA. Brief cognitive?behavioral therapy for temporomandibular disorder pain: effects on daily electronic outcome and process measures. Pain. 2005;117:377–387. doi: 10.1016/j.pain.2005.06.025. [DOI] [PubMed] [Google Scholar]
- Stone AA, Broderick JE, Schwartz JE, Shiffman S, Litcher-Kelly L, Calvanese P. Intensive momentary reporting of pain with an electronic diary: reactivity, compliance, and patient satisfaction. Pain. 2003;104:343–351. doi: 10.1016/S0304-3959(03)00040-X. [DOI] [PubMed] [Google Scholar]
- Litt MD, Shafer D, Napolitano C. Momentary mood and coping processes in TMD pain. Health Psychol. 2004;23:354–362. doi: 10.1037/0278-6133.23.4.354. [DOI] [PubMed] [Google Scholar]
- Roelofs J, Peters ML, Patijn J, Schouten EG, Vlaeyen JW. Electronic diary assessment of pain-related fear, attention to pain, and pain intensity in chronic low back pain patients. Pain. 2004;112:335–342. doi: 10.1016/j.pain.2004.09.016. [DOI] [PubMed] [Google Scholar]
- Giffin NJ, Ruggiero L, Lipton RB, Silberstein SD, Tvedskov JF, Olesen J, Altman J, Goadsby PJ, Macrae A. Premonitory symptoms in migraine: an electronic diary study. Neurology. 2003;60:935–940. doi: 10.1212/01.wnl.0000052998.58526.a9. [DOI] [PubMed] [Google Scholar]
- Affleck G, Urrows S, Tennen H, Higgins P, Abeles M. Sequential daily relations of sleep, pain intensity, and attention to pain among women with fibromyalgia. Pain. 1996;68:363–368. doi: 10.1016/S0304-3959(96)03226-5. [DOI] [PubMed] [Google Scholar]
- Affleck G, Tennen H, Zautra A, Urrows S, Abeles M, Karoly P. Women's pursuit of personal goals in daily life with fibromyalgia: a value-expectancy analysis. J Consult Clin Psychol. 2001;69:587–596. doi: 10.1037/0022-006X.69.4.587. [DOI] [PubMed] [Google Scholar]
- Zautra A, Smith B, Affleck G, Tennen H. Examinations of chronic pain and affect relationships: applications of a dynamic model of affect. J Consult Clin Psychol. 2001;69:786–795. doi: 10.1037/0022-006X.69.5.786. [DOI] [PubMed] [Google Scholar]
- Peters ML, Sorbi MJ, Kruise DA, Kerssens JJ, Verhaak PF, Bensing JM. Electronic diary assessment of pain, disability and psychological adaptation in patients differing in duration of pain. Pain. 2000;84:181–192. doi: 10.1016/S0304-3959(99)00206-7. [DOI] [PubMed] [Google Scholar]
- Honkoop PC, Sorbi MJ, Godaert GL, Spierings EL. High-density assessment of the IHS classification criteria for migraine without aura: a prospective study. Cephalalgia. 1999;19:201–206. doi: 10.1046/j.1468-2982.1999.019004201.x. [DOI] [PubMed] [Google Scholar]
- Viane I, Crombez G, Eccleston C, Devulder J, De Corte W. Acceptance of the unpleasant reality of chronic pain: effects upon attention to pain and engagement with daily activities. Pain. 2004;112:282–288. doi: 10.1016/j.pain.2004.09.008. [DOI] [PubMed] [Google Scholar]
- Stone AA, Broderick JE, Porter LS, Kaell AT. The experience of rheumatoid arthritis pain and fatigue: examining momentary reports and correlates over one week. Arthritis Care Res. 1997;10:185–193. doi: 10.1002/art.1790100306. [DOI] [PubMed] [Google Scholar]
- Buysse DJ, Thompson W, Scott J, Franzen PL, Germain A, Hall M, Moul DE, Nofzinger EA, Kupfer DJ. Daytime symptoms in primary insomnia: a prospective analysis using ecological momentary assessment. Sleep Med. 2007;8:198–208. doi: 10.1016/j.sleep.2006.10.006. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hacker ED, Ferrans CE. Ecological momentary assessment of fatigue in patients receiving intensive cancer therapy. J Pain Symptom Manage. 2007;33:267–275. doi: 10.1016/j.jpainsymman.2006.08.007. [DOI] [PubMed] [Google Scholar]
- Curran SL, Beacham AO, Andrykowski MA. Ecological momentary assessment of fatigue following breast cancer treatment. J Behav Med. 2004;27:425–444. doi: 10.1023/B:JOBM.0000047608.03692.0c. [DOI] [PubMed] [Google Scholar]
- Sonnenschein M, Sorbi MJ, van Doornen LJ, Schaufeli WB, Maas CJ. Evidence that impaired sleep recovery may complicate burnout improvement independently of depressive mood. J Psychosom Res. 2007;62:487–494. doi: 10.1016/j.jpsychores.2006.11.011. [DOI] [PubMed] [Google Scholar]
- Sonnenschein M, Mommersteeg PM, Houtveen JH, Sorbi MJ, Schaufeli WB, van Doornen LJ. Exhaustion and endocrine functioning in clinical burnout: an in-depth study using the experience sampling method. Biol Psychol. 2007;75:176–184. doi: 10.1016/j.biopsycho.2007.02.001. [DOI] [PubMed] [Google Scholar]
- Friedberg F, Quick J. Alexithymia in chronic fatigue syndrome: associations with momentary, recall, and retrospective measures of somatic complaints and emotions. Psychosom Med. 2007;69:54–60. doi: 10.1097/PSY.0b013e31802b873e. [DOI] [PubMed] [Google Scholar]
- Wild B, Eichler M, Feiler S, Friederich HC, Hartmann M, Herzog W, Zipfel S. Dynamic analysis of electronic diary data of obese patients with and without binge eating disorder. Psychother Psychosom. 2007;76:250–252. doi: 10.1159/000101505. [DOI] [PubMed] [Google Scholar]
- Hilbert A, Tuschen-Caffier B. Maintenance of binge eating through negative mood: a naturalistic comparison of binge eating disorder and bulimia nervosa. Int J Eat Disord. 2007;40:521–530. doi: 10.1002/eat.20401. [DOI] [PubMed] [Google Scholar]
- Wonderlich SA, Crosby RD, Engel SG, Mitchell JE, Smyth J, Miltenberger R. Personality-based clusters in bulimia nervosa: differences in clinical variables and ecological momentary assessment. J Personal Disord. 2007;21:340–357. doi: 10.1521/pedi.2007.21.3.340. [DOI] [PubMed] [Google Scholar]
- Wonderlich SA, Rosenfeldt S, Crosby RD, Mitchell JE, Engel SG, Smyth J, Miltenberger R. The effects of childhood trauma on daily mood lability and comorbid psychopathology in bulimia nervosa. J Trauma Stress. 2007;20:77–87. doi: 10.1002/jts.20184. [DOI] [PubMed] [Google Scholar]
- Vansteelandt K, Rijmen F, Pieters G, Probst M, Vanderlinden J. Drive for thinness, affect regulation and physical activity in eating disorders: a daily life study. Behav Res Ther. 2007;45:1717–1734. doi: 10.1016/j.brat.2006.12.005. [DOI] [PubMed] [Google Scholar]
- Boseck JJ, Engel SG, Allison KC, Crosby RD, Mitchell JE, de Zwaan M. The application of ecological momentary assessment to the study of night eating. Int J Eat Disord. 2007;40:271–276. doi: 10.1002/eat.20359. [DOI] [PubMed] [Google Scholar]
- Stein RI, Kenardy J, Wiseman CV, Dounchis JZ, Arnow BA, Wilfley DE. What's driving the binge in binge eating disorder?: A prospective examination of precursors and consequences. Int J Eat Disord. 2007;40:195–203. doi: 10.1002/eat.20352. [DOI] [PubMed] [Google Scholar]
- Engel SG, Boseck JJ, Crosby RD, Wonderlich SA, Mitchell JE, Smyth J, Miltenberger R, Steiger H. The relationship of momentary anger and impulsivity to bulimic behavior. Behav Res Ther. 2007;45:437–447. doi: 10.1016/j.brat.2006.03.014. [DOI] [PubMed] [Google Scholar]
- Wegner KE, Smyth JM, Crosby RD, Wittrock D, Wonderlich SA, Mitchell JE. An evaluation of the relationship between mood and binge eating in the natural environment using ecological momentary assessment. Int J Eat Disord. 2002;32:352–361. doi: 10.1002/eat.10086. [DOI] [PubMed] [Google Scholar]
- Kajander K, Latti M, Hatakka K, Korpela R. An electronic diary versus a paper diary in measuring gastrointestinal symptoms. Dig Liver Dis. 2007;39:288–289. doi: 10.1016/j.dld.2006.11.014. [DOI] [PubMed] [Google Scholar]
- Kamarck TW, Janicko DL, Shiffman S, Polk DE, Muldoon MF, Liebenauer LL, Schwartz JE. Psychosocial demands and ambulatory pressure: a field assessment approach. Physiol Behav. 2002;77:699–704. doi: 10.1016/S0031-9384(02)00921-6. [DOI] [PubMed] [Google Scholar]
- Smyth J, Ockenfels M, Porter L, Kirschbaum C, Hellhammer D, Stone A. The association between daily stressors, mood and salivary cortisol secretion. Psychoneuroendocrinology. 1998;23:353–370. doi: 10.1016/S0306-4530(98)00008-0. [DOI] [PubMed] [Google Scholar]
- Saito M, Kumano H, Yoshiuchi K, Kokubo N, Ohashi K, Yamamoto Y, Shinohara N, Yanagisawa Y, Sakabe K, Miyata M, Ishikawa S, Kuboki T. Symptom Profile of Multiple Chemical Sensitivity in Actual Life. Psychosom Med. 2005;67:318–325. doi: 10.1097/01.psy.0000155676.69030.28. [DOI] [PubMed] [Google Scholar]
- Affleck G, Apter A, Tennen H, Reisine S, Barrows E, Willard A, Unger J, ZuWallack R. Mood states associated with transitory changes in asthma symptoms and peak expiratory flow. Psychosom Med. 2000;62:61–68. doi: 10.1097/00006842-200001000-00009. [DOI] [PubMed] [Google Scholar]
- Smyth J, Soefer M, Hurewitz A, Kliment A, Stone A. Daily psychosocial factors predict levels and diurnal cycles of asthma symptomatology and peak flow. J Behav Med. 1999;22:179–193. doi: 10.1023/A:1018787500151. [DOI] [PubMed] [Google Scholar]
- Kikuchi H, Yoshiuchi K, Ohashi K, Yamamoto Y, Akabayashi A. Tension-type headache and physical activity: an actigraphic study. Cephalalgia. 2007;27:1236–1243. doi: 10.1111/j.1468-2982.2007.01436.x. [DOI] [PubMed] [Google Scholar]
- Liszka-Hackzell JJ, Martin DP. An analysis of the relationship between activity and pain in chronic and acute low back pain. Anesth Analg. 2004;99:477–481. doi: 10.1213/01.ANE.0000132696.15310.DD. [DOI] [PubMed] [Google Scholar]
- Kop WJ, Lyden A, Berlin AA, Ambrose K, Olsen C, Gracely RH, Williams DA, Clauw DJ. Ambulatory monitoring of physical activity and symptoms in fibromyalgia and chronic fatigue syndrome. Arthritis Rheum. 2005;52:296–303. doi: 10.1002/art.20779. [DOI] [PubMed] [Google Scholar]
- Bazelmans E, Bleijenberg G, Voeten MJ, Meer JW van der, Folgering H. Impact of a maximal exercise test on symptoms and activity in chronic fatigue syndrome. J Psychosom Res. 2005;59:201–208. doi: 10.1016/j.jpsychores.2005.04.003. [DOI] [PubMed] [Google Scholar]
- Ohashi K, Yamamoto Y, Natelson BH. Activity rhythm degrades after strenuous exercise in chronic fatigue syndrome. Physiol Behav. 2002;77:39–44. doi: 10.1016/S0031-9384(02)00808-9. [DOI] [PubMed] [Google Scholar]
- Yoshiuchi K, Yamamoto Y, Niwamoto H, Watsuji T, Kumano H, Kuboki T. Behavioral power-law exponents in the usage of electric appliances correlate mood states in the elderly. Int J Sport Health Sci. 2003;1:41–47. [Google Scholar]
- Ohashi K, Bleijenberg G, Werf S van der, Prins J, Amaral LA, Natelson BH, Yamamoto Y. Decreased fractal correlation in diurnal physical activity in chronic fatigue syndrome. Methods Inform Med. 2004;43:26–29. [PubMed] [Google Scholar]
- Nakamura T, Kiyono K, Yoshiuchi K, Nakahara R, Struzik ZR, Yamamoto Y. Universal scaling law in human behavioral organization. Phys Rev Lett. 2007;99:138103–1. doi: 10.1103/PhysRevLett.99.138103. [DOI] [PubMed] [Google Scholar]
- Yamamoto Y, LaManca JJ, Natelson BH. A measure of heart rate variability is sensitive to orthostatic challenge in women with chronic fatigue syndrome. Exp Biol Med. 2003;228:167–174. doi: 10.1177/153537020322800206. [DOI] [PubMed] [Google Scholar]
- Peckerman A, LaManca JJ, Qureishi B, Dahl KA, Golfetti R, Yamamoto Y, Natelson BH. Baroreceptor reflex and integrative stress responses in chronic fatigue syndrome. Psychosom Med. 2003;65:889–895. doi: 10.1097/01.PSY.0000079408.62277.3D. [DOI] [PubMed] [Google Scholar]
- Yoshiuchi K, Quigley KS, Ohashi K, Yamamoto Y, Natelson BH. Use of time-frequency analysis to investigate temporal patterns of cardiac autonomic response during head-up tilt in chronic fatigue syndrome. Auton Neurosci. 2004;113:55–62. doi: 10.1016/j.autneu.2004.05.001. [DOI] [PubMed] [Google Scholar]
- Yoshiuchi K, Nakahara R, Kumano H, Kuboki T, Togo F, Watanabe E, Yasunaga A, Park MH, Shephard RJ, Aoyagi Y. Yearlong physical activity and depressive symptoms in older Japanese adults: cross-sectional data from the Nakanojo Study. Am J Geriatr Psychiatry. 2006;14:621–624. doi: 10.1097/01.JGP.0000200602.70504.9c. [DOI] [PubMed] [Google Scholar]
- Aoyagi N, Ohashi K, Tomono S, Yamamoto Y. Temporal contribution of body movement to very long-term heart rate variability in humans. Am J Physiol Heart Circ Physiol. 2000;278:H1035–1041. doi: 10.1152/ajpheart.2000.278.4.H1035. [DOI] [PubMed] [Google Scholar]
- Struzik ZR, Yoshiuchi K, Sone M, Ishikawa T, Kikuchi H, Kumano H, Watsuji T, Natelson BH, Yamamoto Y. "Mobile Nurse" platform for ubiquitous medicine. Methods Inform Med. 2007;46:130–134. [PubMed] [Google Scholar]
- Newman MG, Kenardy J, Herman S, Taylor CB. Comparison of palmtop-computer-assited brief cognitive-behavioral treatment to cognitive-behavioral treatment for panic disorder. J Consult Clin Psychol. 1997;65:178–183. doi: 10.1037/0022-006X.65.1.178. [DOI] [PubMed] [Google Scholar]
- Newman MG, Consoli AJ, Taylor CB. A palmtop computer program for the treatment of generalized anxiety disorder. Behav Modif. 1999;23:597–619. doi: 10.1177/0145445599234005. [DOI] [PubMed] [Google Scholar]
- Przeworski A, Newman MG. Palmtop computer-assisted group therapy for social phobia. J Clin Psychol. 2004;60:179–188. doi: 10.1002/jclp.10246. [DOI] [PubMed] [Google Scholar]
- Tate DG, Wing RR, Winett RA. Using Internet technology to deliver a behavioral weight loss program. JAMA. 2001;285:1172–1177. doi: 10.1001/jama.285.9.1172. [DOI] [PubMed] [Google Scholar]
- Harvey-Berino J, Pintauro S, Buzzell P, Gold EC. Effect of Internet support on the long-term maintenance of weight loss. Obes Res. 2004;12:320–329. doi: 10.1038/oby.2004.40. [DOI] [PubMed] [Google Scholar]
- Tate DF, Jackvony EH, Wing RR. Effects of Internet behavioral counselling on weight loss in adults at risk for Type 2 diabetes. JAMA. 2003;289:1833–1836. doi: 10.1001/jama.289.14.1833. [DOI] [PubMed] [Google Scholar]

