Idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF): a systematic review of identifying criteria

BACKGROUND

Idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) remains a complex and unclear phenomenon, often characterized by the report of various, non-specific physical symptoms (NSPS) when an EMF source is present or perceived by the individual. The lack of validated criteria for defining and assessing IEI-EMF affects the quality of the relevant research, hindering not only the comparison or integration of study findings, but also the identification and management of patients by health care providers. The objective of this review was to evaluate and summarize the criteria that previous studies employed to identify IEI-EMF participants.

METHODS

An extensive literature search was performed for studies published up to June 2011. We searched EMBASE, Medline, Psychinfo, Scopus and Web of Science. Additionally, citation analyses were performed for key papers, reference sections of relevant papers were searched, conference proceedings were examined and a literature database held by the Mobile Phones Research Unit of King's College London was reviewed.

RESULTS

Sixty-three studies were included. "Hypersensitivity to EMF" was the most frequently used descriptive term. Despite heterogeneity, the criteria predominantly used to identify IEI-EMF individuals were: 1. Self-report of being (hyper)sensitive to EMF. 2. Attribution of NSPS to at least one EMF source. 3. Absence of medical or psychiatric/psychological disorder capable of accounting for these symptoms 4. Symptoms should occur soon (up to 24 hours) after the individual perceives an exposure source or exposed area. (Hyper)sensitivity to EMF was either generalized (attribution to various EMF sources) or source-specific. Experimental studies used a larger number of criteria than those of observational design and performed more frequently a medical examination or interview as prerequisite for inclusion.

CONCLUSIONS

Considerable heterogeneity exists in the criteria used by the researchers to identify IEI-EMF, due to explicit differences in their conceptual frameworks. Further work is required to produce consensus criteria not only for research purposes but also for use in clinical practice. This could be achieved by the development of an international protocol enabling a clearly defined case definition for IEI-EMF and a validated screening tool, with active involvement of medical practitioners.

Ticking all the boxes? A systematic review of education and communication interventions to prevent tick-borne disease

Tick-borne disease has become increasingly prevalent across Europe. Despite the effectiveness of protective behaviors, relatively few people adopt them when in areas where ticks are known to be present. In this systematic review we identified studies that assessed the impact of any educational or behavioral interventions intended to encourage the widespread use of protective behaviors against tick-borne disease. An extensive search of electronic databases returned a total of only nine such studies. Only two of these were fully randomized controlled trials, with the remaining studies using weaker designs and often relying solely on self-reports to assess behavior. The majority of research in this area has not explicitly noted the consideration of any formal psychological theory on how best to promote behaviors that protect health. Nonetheless, the results show that both knowledge of and attitudes towards tick-borne disease are amenable to change, although the stability of these changes over time has not yet been determined. Not all intervention strategies have proved effective, with some producing detrimental effects. More theory-based, methodologically-robust studies are urgently required if we are to gain a better understanding of the most effective strategies for encouraging members of the public to adopt behaviors known to protect against tick-borne disease.

The London polonium incident: lessons in risk communications

Public responses to large-scale radiological incidents are often thought to be disproportionate to the objective risk and can involve widespread societal disruption. Recent experiences of the (200)Po incident in central London suggest that public responses depend heavily on the nature of the incident and the effectiveness of risk communication efforts. This paper describes the outcome of several studies done in the aftermath of the (200)Po incident that suggest the reaction of the public on this occasion was muted, even for those directly affected. However, the desire for accurate, up-to-date and individually-tailored information was strong, and satisfaction with the efforts of the responding agencies was mediated by this information provision. A small minority of individuals was difficult to reassure effectively. This group may confer a particular drain on resources. Lessons for the risk communication efforts of public health responders are identified, in particular the importance of helping individuals to identify their risk of exposure, understand the difference between acute and chronic effects of exposure, and appreciate the meaning of any test results. Attempts at providing reassurance in the absence of specific information are likely to be counterproductive in any future radiological incident.

Do people with idiopathic environmental intolerance attributed to electromagnetic fields display physiological effects when exposed to electromagnetic fields? A systematic review of provocation studies

Idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) is a controversial illness in which people report symptoms that they believe are triggered by exposure to EMF. Double-blind experiments have found no association between the presence of EMF and self-reported outcomes in people with IEI-EMF. No systematic review has assessed whether EMF exposure triggers physiological or cognitive changes in this group. Using a systematic literature search, we identified 29 single or double-blind experiments in which participants with IEI-EMF were exposed to different EMF levels and in which objectively measured outcomes were assessed. Five studies identified significant effects of exposure such as reduced heart rate and blood pressure, altered pupillary light reflex, reduced visual attention and perception, improved spatial memory, movement away from an EMF source during sleep and altered EEG during sleep. In most cases, these were isolated results that other studies failed to replicate. For the sleep EEG findings, the results reflected similar changes in the IEI-EMF participants and a non-IEI-EMF control group. At present, there is no reliable evidence to suggest that people with IEI-EMF experience unusual physiological reactions as a result of exposure to EMF. This supports suggestions that EMF is not the main cause of their ill health.

Using electronic patient records to assess the impact of swine flu (influenza H1N1) on mental health patients

BACKGROUND

Electronic patient records are increasingly used in primary care research, but rarely in psychiatric research. Little is known about how people with pre-existing mental illness respond to public health threats.

AIMS

To outline the swine flu related concerns and behaviours of mental health patients and to determine whether marked concern was associated with any specific demographic or diagnostic groups.

METHODS

We searched a database containing electronic patient records from a large mental health trust for references to swine flu made between 15 April and 15 July 2009. Thematic analysis was used to code swine flu related concerns and behaviours. A case-control approach sought to determine whether there were demographic or diagnostic associations with expressing moderate/severe concern about swine flu.

RESULTS

A range of swine flu related behaviours were noted and considerable impact was recorded for some patients. Children and patients with neurotic and somatoform disorders were over-represented amongst those expressing moderate/severe swine flu concerns.

CONCLUSION

Research databases using electronic clinical records are a useful way to track responses to emerging public health threats. Children receiving mental health care and patients with neurotic and somatoform disorders may be particularly psychologically vulnerable to infectious disease epidemics.

An individual-based simulation of pneumonic plague transmission following an outbreak and the significance of intervention compliance

The existence of primary pneumonic plague outbreaks raises concerns over the use of the causative bacteria as an aerosol-based bioweapon. We employed an individual-based model, parameterised using published personal contact information, to assess the severity of a deliberate release in a discrete community, under the influence of two proposed intervention strategies. We observed that the severity of the resulting epidemic is determined by the degree of personal compliance with said strategies, implying that prior preparedness activities are essential in order that public awareness and willingness to seek treatment is achieved quickly.

The impact of communications about swine flu (influenza A H1N1v) on public responses to the outbreak: results from 36 national telephone surveys in the UK

OBJECTIVES

To assess the association between levels of worry about the possibility of catching swine flu and the volume of media reporting about it; the role of psychological factors in predicting likely uptake of the swine flu vaccine; and the role of media coverage and advertising in predicting other swine flu-related behaviours.

DESIGN

Data from a series of random-digit-dial telephone surveys were analysed. A time series analysis tested the association between levels of worry and the volume of media reporting on the start day of each survey. Cross-sectional regression analyses assessed the relationships between likely vaccine uptake or behaviour and predictor variables.

SETTING

Thirty-six surveys were run at, on average, weekly intervals across the UK between 1 May 2009 and 10 January 2010. Five surveys (run between 14 August and 13 September) were used to assess likely vaccine uptake. Five surveys (1-17 May) provided data relating to other behaviours.

PARTICIPANTS

Between 1047 and 1173 people aged 16 years or over took part in each survey: 5175 participants provided data about their likely uptake of the swine flu vaccine; 5419 participants provided data relating to other behaviours.

MAIN OUTCOME MEASURES

All participants were asked to state how worried they were about the possibility of personally catching swine flu. Subsets were asked how likely they were to take up a swine flu vaccination if offered it and whether they had recently carried tissues with them, bought sanitising hand gel, avoided using public transport or had been to see a general practitioner, visited a hospital or called NHS Direct for a flu-related reason.

RESULTS

The percentage of 'very' or 'fairly' worried participants fluctuated between 9.6% and 32.9%. This figure was associated with the volume of media reporting, even after adjusting for the changing severity of the outbreak [chi2(1) = 6.6, p = 0.010, coefficient for log-transformed data = 2.6]. However, this effect only occurred during the UK's first summer wave of swine flu. In total, 56.1% of respondents were very or fairly likely to accept the swine flu vaccine. The strongest predictors were being very worried about the possibility of oneself [adjusted odds ratio (aOR) 4.7, 95% confidence interval (CI) 3.2 to 7.0] or one's child (aOR 8.0, 95% CI 4.6 to 13.9) catching swine flu. Overall, 33.1% of participants reporting carrying tissues with them, 9.5% had bought sanitising gel, 2.0% had avoided public transport and 1.6% had sought medical advice. Exposure to media coverage or advertising about swine flu increased tissue carrying or buying of sanitising hand gel, and reduced avoidance of public transport or consultation with health services during early May 2009. Path analyses showed that media coverage and advertising had these differential effects because they raised the perceived efficacy of hygiene behaviours but decreased the perceived efficacy of avoidance behaviours.

CONCLUSIONS

During the swine flu outbreak, uptake rates for protective behaviours and likely acceptance rates for vaccination were low. One reason for this may in part be explained by was the low level of public worry about the possibility of catching swine flu. When levels of worry are generally low, acting to increase the volume of mass media and advertising coverage is likely to increase the perceived efficacy of recommended behaviours, which, in turn, is likely to increase their uptake.

New influenza A/H1N1 ("swine flu"): information needs of airport passengers and staff

Please cite this paper as: Dickmann et al. (2010) New Influenza A/H1N1 (“Swine Flu”): information needs of airport passengers and staff. . Influenza and Other Respiratory Viruses 5(1), 39–46.

Background  Airports are the entrances of infectious diseases. Particularly at the beginning of an outbreak, information and communication play an important role to enable the early detection of signs or symptoms and to encourage passengers to adopt appropriate preventive behaviour to limit the spread of the disease.

Objectives  To determine the adequacy of the information provided to airport passengers and staff in meeting their information needs in relation to their concerns.

Methods  At the start of the influenza A/H1N1 epidemic (29–30 April 2009), qualitative semi‐structured interviews (N = 101) were conducted at Frankfurt International Airport with passengers who were either returning from or going to Mexico and with airport staff who had close contact with these passengers. Interviews focused on knowledge about swine flu, information needs and fear or concern about the outbreak.

Results  The results showed that a desire for more information was associated with higher concern – the least concerned participants did not want any additional information, while the most concerned participants reported a range of information needs. Airport staff in contact with passengers travelling from the epicentre of the outbreak showed the highest levels of fear or concern, coupled with a desire to be adequately briefed by their employer.

Conclusions  Our results suggest that information strategies should address not only the exposed or potentially exposed but also groups that feel at risk. Identifying what information these different passenger and staff groups wish to receive will be an important task in any future infectious disease outbreak.

Idiopathic environmental intolerance attributed to electromagnetic fields (formerly 'electromagnetic hypersensitivity'): An updated systematic review of provocation studies

Idiopathic Environmental Intolerance attributed to electromagnetic fields (IEI-EMF; formerly 'electromagetic hypersensitivity') is a medically unexplained illness in which subjective symptoms are reported following exposure to electrical devices. In an earlier systematic review, we reported data from 31 blind provocation studies which had exposed IEI-EMF volunteers to active or sham electromagnetic fields and assessed whether volunteers could detect these fields or whether they reported worse symptoms when exposed to them. In this article, we report an update to that review. An extensive literature search identified 15 new experiments. Including studies reported in our earlier review, 46 blind or double-blind provocation studies in all, involving 1175 IEI-EMF volunteers, have tested whether exposure to electromagnetic fields is responsible for triggering symptoms in IEI-EMF. No robust evidence could be found to support this theory. However, the studies included in the review did support the role of the nocebo effect in triggering acute symptoms in IEI-EMF sufferers. Despite the conviction of IEI-EMF sufferers that their symptoms are triggered by exposure to electromagnetic fields, repeated experiments have been unable to replicate this phenomenon under controlled conditions. A narrow focus by clinicians or policy makers on bioelectromagnetic mechanisms is therefore, unlikely to help IEI-EMF patients in the long-term.

Perceptions and reactions with regard to pneumonic plague

We assessed perceptions and likely reactions of 1,005 UK adults to a hypothetical terrorist attack involving pneumonic plague. Likely compliance with official recommendations ranged from good (98% would take antimicrobial drugs) to poor (76% would visit a treatment center). Perceptions about plague were associated with these intentions.

Public perceptions, anxiety, and behaviour change in relation to the swine flu outbreak: cross sectional telephone survey

OBJECTIVE

To assess whether perceptions of the swine flu outbreak predicted changes in behaviour among members of the public in England, Scotland, and Wales.

DESIGN

Cross sectional telephone survey using random digit dialling.

SETTING

Interviews by telephone between 8 and 12 May.

PARTICIPANTS

997 adults aged 18 or more who had heard of swine flu and spoke English.

MAIN OUTCOME MEASURES

Recommended change in behaviour (increases in handwashing and surface cleaning or plans made with a "flu friend") and avoidance behaviours (engaged in one or more of six behaviours such as avoiding large crowds or public transport).

RESULTS

37.8% of participants (n=377) reported performing any recommended behaviour change "over the past four days . . . because of swine flu." 4.9% (n=49) had carried out any avoidance behaviour. Controlling for personal details and anxiety, recommended changes were associated with perceptions that swine flu is severe, that the risk of catching it is high risk, that the outbreak will continue for a long time, that the authorities can be trusted, that good information has been provided, that people can control their risk of catching swine flu, and that specific behaviours are effective in reducing the risk. Being uncertain about the outbreak and believing that the outbreak had been exaggerated were associated with a lower likelihood of change. The strongest predictor of behaviour change was ethnicity, with participants from ethnic minority groups being more likely to make recommended changes (odds ratio 3.2, 95% confidence interval 2.0 to 5.3) and carry out avoidance behaviours (4.1, 2.0 to 8.4).

CONCLUSIONS

The results support efforts to inform the public about specific actions that can reduce the risks from swine flu and to communicate about the government's plans and resources. Tackling the perception that the outbreak has been "over-hyped" may be difficult but worthwhile. Additional research is required into differing reactions to the outbreak among ethnic groups.

Methodological challenges in assessing general population reactions in the immediate aftermath of a terrorist attack

Assessing mental health needs following a disaster is important, particularly within high-risk groups such as first responders or individuals who found themselves directly caught up in the incident. Particularly following events involving widespread destruction, ingenuity and hard work are required to successfully study these issues. When considering responses among the general population following less devastating events such as a conventional terrorist attack, or following an event involving a chemical, biological, radiological or nuclear agent, other variables may become more relevant for determining the population's overall psychosocial well-being. Trust, perceived risk, sense of safety, willingness to take prophylaxis and unnecessary attendance at medical facilities will all be important in determining the overall psychological, medical, economic and political impact of such attacks. Assessing these variables can help government agencies and non-governmental organizations to adjust their communication and outreach efforts. As there is often a need to provide these data quickly, telephone surveys using short time-windows for data collection or which use quota samples are often required. It is unclear whether slower, more conventional and more expensive survey methods with better response rates would produce results different enough to these quicker and cheaper methods to have a major impact on any resulting policy decisions. This empirical question would benefit from further study.

Can evidence change belief? Reported mobile phone sensitivity following individual feedback of an inability to discriminate active from sham signals

OBJECTIVE

In this study, we tested whether providing individuals, who described being sensitive to mobile phone signals, with accurate feedback about their ability to discriminate an active mobile phone signal from a sham signal had any impact on their subsequent symptom levels or their perceived sensitivity to mobile phones.

METHODS

Sixty-nine participants who reported sensitivity to mobile phones took part in a double-blind, placebo-controlled provocation study. Perceived sensitivity to mobile phones was assessed using a version of the Sensitive Soma Assessment Scale (SSAS) and the severity of any symptoms attributed to mobile phones was recorded. Both the overall ("negative") findings of the provocation study and the participant's own individual results ("correct" or "incorrect" at detecting a mobile phone signal) were then described to them. Six months later, perceived sensitivity and symptom severity were measured again.

RESULTS

Fifty-eight participants (84%) received feedback and participated in the 6-month follow-up. No significant differences in SSAS scores or in symptom severity scores were found between individuals told that they were correct (n=31) or incorrect (n=27) in their ability to detect mobile phone signals in the provocation study.

CONCLUSION

The provision of accurate feedback was insufficient to change attributions or reduce symptoms in this study. However, an overtly negative reaction to feedback was not observed among most participants, and some participants were willing to consider that factors other than electromagnetic field may be relevant in causing or exacerbating their symptoms. Discussing possible psychological factors with electromagnetic hypersensitivity patients may be beneficial for some.

Public information needs after the poisoning of Alexander Litvinenko with polonium-210 in London: cross sectional telephone survey and qualitative analysis

OBJECTIVES

To identify public perceptions of the risk to health after the poisoning of Alexander Litvinenko with polonium-210 (210Po) in London and to assess the impact of public health communications.

DESIGN

Cross sectional telephone survey and qualitative interviews.

SETTING

London, United Kingdom.

PARTICIPANTS

1000 people completed the cross sectional survey and 86 potentially exposed people completed the qualitative interviews.

MAIN OUTCOME MEASURES

Perception of risk to personal health after the 210Po incident. Qualitative interviews were analysed with an emphasis on information needs.

RESULTS

11.7% of the survey sample (n=117) perceived their health to be at risk. Aside from personal variables the main predictors of perceived risk to health were believing that the incident was related to terrorism (odds ratio 2.7, 95% confidence interval 1.5 to 4.6) rather than to espionage, that it was targeted at the wider public rather than one person (5.9, 3.2 to 10.9), and that it could affect people who had not been in the contaminated area (3.2, 2.1 to 5.1). Participants in the qualitative interviews were generally satisfied with the information they had received, although they would have preferred more information about their individual risk of exposure, the results of their urine tests, and the health implications of the incident.

CONCLUSIONS

Perceptions of the public that the 210Po incident in London in 2006 was related to espionage helped to reassure them that the risks to personal health were low. In the event of future incidents it is important to ensure that detailed, comprehensible information about the risks of any exposure is available.

Multiple chemical sensitivities: review

PURPOSE OF REVIEW

There have been a number of recent studies examining behavioural and social factors in the potential cause of Multiple Chemical Sensitivities, or Idiopathic Environmental Intolerance. The current review will draw together recent research and suggest directions for future investigation.

RECENT FINDINGS

Recent studies have implicated a number of different perspectives which may be helpful in understanding the cause of chemical sensitivities. A multifactorial model incorporating behavioural, physiological and sociological approaches may be useful. Cultural and historical factors, alongside individual expectations and beliefs, as well as maladaptive learning and conditioning processes, may be important in the specific cause of chemical sensitivities. Iatrogenesis, through the promise of unproven 'therapies', may perpetuate reported symptoms further. Although there are many recent experiments implicating potential behavioural or psychological causes for Multiple Chemical Sensitivities, there remains a paucity of treatment trials for this condition.

SUMMARY

Good-quality treatment trials examining psychological/behavioural approaches in the management of Multiple Chemical Sensitivities are urgently needed.

Mediating the social and psychological impacts of terrorist attacks: the role of risk perception and risk communication

The public's understanding of chemical, biological, radiological and nuclear (CBRN) related issues and their likely actions following a CBRN incident is an issue of great concern, as public psychological and behavioural responses will help determine subsequent morbidity and mortality rates. This paper explores the role of effective government communication with the public and its role in mediating the social and psychological impact of terrorist attacks. We examine the importance of effective communication in reducing morbidity and mortality in the event of a terrorist attack and explore the impact of risk perceptions in determining the success or failure of risk communication strategies. This includes the examination of the role of fear as a health risk, and the identification of factors relevant to public trust in risk communication. Finally, an investigation of the type of information desired by members of the public leads the authors to make risk communication recommendations targeted at the promotion of more adaptive behaviours in response to CBRN attacks.

Enduring consequences of terrorism: 7-month follow-up survey of reactions to the bombings in London on 7 July 2005

BACKGROUND

Terrorist attacks can have psychological effects on the general public.

AIMS

To assess the medium-term effects of the July 2005 London bombings on the general population in London and to identify risk factors for persistent effects.

METHOD

We telephoned 1010 Londoners 11-13 days after the bombings to assess stress levels, perceived threat and travel intentions. Seven months later, 574 respondents were contacted again and asked similar questions, and questions concerning altered perceptions of self and the world.

RESULTS

;Substantial stress' (11%), perceived threat to self (43%) and reductions in travel because of the bombings (19%) persisted at a reduced level; other perceived threats remained unchanged. A more negative world view was common. Other than degree of exposure to the bombings, there were no consistent predictors of which people with short-term reactions would develop persistent reactions.

CONCLUSIONS

A longer-term impact of terrorism on the perceptions and behaviour of Londoners was documented.

Multiple chemical sensitivities: A systematic review of provocation studies

A systematic review of provocation studies of persons reporting multiple chemical sensitivities (MCS) was conducted from databases searched from inception to May 2006. Thirty-seven studies were identified, testing 784 persons reporting MCS, 547 control subjects, and 180 individuals of whom a subset were chemically sensitive. Blinding was inadequate in most studies. In 21 studies odors of chemicals were probably apparent; 19 of these reported positive responses to provocations among chemically sensitive individuals, and 1 study demonstrated that negative expectations were significantly associated with increased symptom reporting after provocations. Seven studies used chemicals at or below odor thresholds, and 6 failed to show consistent responses among sensitive individuals after active provocation. Six studies used forced-choice discrimination and demonstrated that chemically sensitive individuals were not better at detecting odor thresholds than nonsensitive participants. Three studies tested individuals by using nose clips/face masks and confirmed response, possibly mediated through eye exposure. Three studies used olfactory masking agents to conceal stimuli, and none of these found associations between provocations and response. We conclude that persons with MCS do react to chemical challenges; however, these responses occur when they can discern differences between active and sham substances, suggesting that the mechanism of action is not specific to the chemical itself and might be related to expectations and prior beliefs.

Viewpoint: Terrorism and Dispelling the Myth of a Panic Prone Public

Governments and commentators perceive the public to be prone to panic in response to terrorist attacks--conventional or involving chemical, biological or radiological weapons. Evidence from five such incidents suggests that the public is not prone to panic, although people can change their behaviours and attitudes to reduce the risk of themselves being exposed to a terrorist incident. Behavioural responses may be divided into acts of omission, such as not making unnecessary journeys, and acts of commission, such as taking prophylactic medication despite the inherent risk of side effects. Evidence suggests that the public are aware of these differences, and tend to adopt responses proportionate to the risk. Drawing upon the literature in the social and natural sciences, our discussion encompasses differing risk perceptions of terrorist threats and consequences of attacks. How do fear and anxiety interact with behavioural responses to amplify or attenuate perceptions that can be modified through risk communication undertaken by authorities?

Long-lasting T cell responses to biological warfare vaccines in human vaccinees

BACKGROUND

Medical countermeasures against biological warfare include the use of vaccines for anthrax and plague, which require repeated dosing and adjuvant to achieve adequate protection from threats such as inhalational anthrax and pneumonic plague. Despite the widespread use of these measures in preparation for recent military deployments, little is known about the cell-mediated immune response that is induced by these vaccines, in comparison with conventional vaccines, such as pertussis or tetanus-diphtheria vaccines.

METHODS

To examine this question, we used cytokine enzyme-linked immunospot assays to measure interferon-gamma, interleukin (IL)-2, IL-4, and IL-13-producing cells in military service personnel vaccinated during the Gulf War of 1990-1991.

RESULTS

Our data indicate that 12-15 years after vaccination against anthrax and plague, antigen-specific T cell recall responses are present in the circulation and are comparable in magnitude to those for tetanus-diphtheria toxoids. Recall responses to anthrax were an approximately equal mixture of type 1 T helper cell (interferon-gamma and IL-2) and type 2 T helper cell (predominantly IL-13) responses, whereas plague cellular immunity was more polarized toward type 1 T helper cell responses. Responder cell frequency and type were similar to that against conventional tetanus-diphtheria (mixed type 1 and type 2 T helper cells) vaccine. When veterans were divided according to whether or not they reported multisymptom illness, there was no difference in the frequency or type of cellular response, although the number of cases in each group was small, and these data should be interpreted as preliminary.

CONCLUSIONS

This study shows that, despite any putative limitations of vaccines for anthrax and plague in terms of achieving protective host immunity, long-lasting cell-mediated responses are generated with these agents.

Are some people sensitive to mobile phone signals? Within participants double blind randomised provocation study

OBJECTIVE

To test whether people who report being sensitive to mobile phone signals have more symptoms when exposed to a pulsing mobile signal than when exposed to a sham signal or a non-pulsing signal.

DESIGN

Double blind, randomised, within participants provocation study.

SETTING

Dedicated suite of offices at King's College London, between September 2003 and June 2005.

PARTICIPANTS

60 "sensitive" people who reported often getting headache-like symptoms within 20 minutes of using a global system for mobile communication (GSM) mobile phone and 60 "control" participants who did not report any such symptoms.

INTERVENTION

Participants were exposed to three conditions: a 900 MHz GSM mobile phone signal, a non-pulsing carrier wave signal, and a sham condition with no signal present. Each exposure lasted for 50 minutes.

MAIN OUTCOME MEASURES

The principal outcome measure was headache severity assessed with a 0-100 visual analogue scale. Other outcomes included six other subjective symptoms and participants' ability to judge whether a signal was present.

RESULTS

Headache severity increased during exposure and decreased immediately afterwards. However, no strong evidence was found of any difference between the conditions in terms of symptom severity. Nor did evidence of any differential effect of condition between the two groups exist. The proportion of sensitive participants who believed a signal was present during GSM exposure (60%) was similar to the proportion who believed one was present during sham exposure (63%).

CONCLUSIONS

No evidence was found to indicate that people with self reported sensitivity to mobile phone signals are able to detect such signals or that they react to them with increased symptom severity. As sham exposure was sufficient to trigger severe symptoms in some participants, psychological factors may have an important role in causing this condition.

TRIAL REGISTRATION

ISRCTN81432775.

A systematic review of treatments for electromagnetic hypersensitivity

BACKGROUND

Electromagnetic hypersensitivity (EHS) is a poorly understood condition in which patients report symptoms following perceived exposure to weak electromagnetic fields (EMFs) such as those produced by mobile phones or visual display units. Little is known about the aetiology of the condition although experimental data suggest that EMFs are an unlikely causal agent. In this systematic review we assessed the efficacy of any treatment for people reporting EHS.

METHODS

Twelve literature databases were examined to identify relevant studies. We also hand-searched conference proceedings and examined the reference sections of reviews and other papers. Only clinical trials that compared the efficacy of a potential treatment for EHS against a control condition were included in the review.

RESULTS

Nine controlled clinical trials were identified, examining the effects of cognitive behavioural therapy (4 studies), visual display unit screen filters (2 studies), 'shielding' EMF emitters (1 study), supplementary antioxidant therapy (1 study) and acupuncture (1 study). The quality of these studies was limited. Nevertheless, their results suggest that cognitive behavioural therapy is more effective than providing no treatment. None of the other therapies have had their efficacy adequately demonstrated.

CONCLUSIONS

The evidence base concerning treatment options for EHS is limited and more research is needed before any definitive clinical recommendations can be made. However, the best evidence currently available suggests that cognitive behavioural therapy is effective for patients who report being hypersensitive to weak EMFs.

Psychological and behavioural reactions to the bombings in London on 7 July 2005: cross sectional survey of a representative sample of Londoners

OBJECTIVES

To assess the impact of the bombings in London on 7 July on stress levels and travel intentions in London's population.

DESIGN

A cross sectional telephone survey using random digit dialling was conducted to contact a representative sample of adults. Respondents were asked to participate in an interview enquiring about current levels of stress and travel intentions.

SETTING

Interviews took place between 18 and 20 July.

PARTICIPANTS

1010 participants (10% of the eligible people we contacted) completed the interviews.

MAIN OUTCOME MEASURES

Main outcomes were presence of substantial stress, measured by using an identical tool to that used to assess the emotional impact of 11 September 2001 in the US population, and intention to travel less on tubes, trains, and buses, or into central London, once the transport network had returned to normal.

RESULTS

31% of Londoners reported substantial stress and 32% reported an intention to travel less. Among other things, having difficulty contacting friends or family by mobile phone (odds ratio 1.7, 95% confidence interval 1.1 to 2.7), having thought you could have been injured or killed (3.8, 2.4 to 6.2), and being Muslim (4.0, 2.5 to 6.6) were associated with a greater presence of substantial stress, whereas being white (0.3, 0.2 to 0.4) and having previous experience of terrorism (0.6, 0.5 to 0.9) were associated with reduced stress. Only 12 participants (1%) felt that they needed professional help to deal with their emotional response to the attacks.

CONCLUSIONS

Although the psychological needs of those intimately caught up in the attacks will require further assessment, we found no evidence of a widespread desire for professional counselling. The attacks have inflicted disproportionately high levels of distress among non-white and Muslim Londoners.

Salivary cortisol as a predictor of postoperative fatigue

OBJECTIVE

Some patients with chronic fatigue syndrome (CFS) exhibit low basal cortisol levels, but it is not known whether low cortisol is a cause of CFS, predates the onset of CFS symptoms, or is an epiphenomenon caused by the behavioral changes typical of CFS. Because elective surgery is one of the few predictable risk factors for chronic fatigue, in this study, we followed a cohort of surgery patients from before to 6 months after their operation to test these theories.

METHOD

One hundred sixty-one patients completed fatigue questionnaires and provided salivary cortisol samples before undergoing an elective inpatient surgical procedure, and then 2 days, 3 weeks, and 6 months afterward.

RESULTS

Controlling for relevant demographic and surgical variables and for preoperative fatigue, low preoperative cortisol did not predict postoperative fatigue severity on any occasion (p > .05). Similarly, there was no correlation between low postoperative cortisol and postoperative fatigue severity at 3 weeks or 6 months (p > .05). Although 16 patients met our case definition for "chronic fatigue" at the 6-month follow up, low preoperative and low postoperative cortisol did not significantly predict fatigue caseness (p > .05).

CONCLUSIONS

Any association between chronic fatigue and low cortisol would seem to develop after the onset of fatigue symptoms. Low cortisol is therefore unlikely to be the primary cause of chronic fatigue states.

Electromagnetic hypersensitivity: a systematic review of provocation studies

OBJECTIVES

The objectives of this study were to assess whether people who report hypersensitivity to weak electromagnetic fields (EMFs) are better at detecting EMF under blind or double-blind conditions than nonhypersensitive individuals, and to test whether they respond to the presence of EMF with increased symptom reporting.

METHODS

An extensive systematic search was used to identify relevant blind or double-blind provocation studies. This involved searching numerous literature databases and conference proceedings, and examining the citations of reviews and included studies. The results of relevant studies were tabulated and metaanalyses were used to compare the proportions of "hypersensitive" and control participants able to discriminate active from sham EMF exposures.

RESULTS

Thirty-one experiments testing 725 "electromagnetically hypersensitive" participants were identified. Twenty-four of these found no evidence to support the existence of a biophysical hypersensitivity, whereas 7 reported some supporting evidence. For 2 of these 7, the same research groups subsequently tried and failed to replicate their findings. In 3 more, the positive results appear to be statistical artefacts. The final 2 studies gave mutually incompatible results. Our metaanalyses found no evidence of an improved ability to detect EMF in "hypersensitive" participants.

CONCLUSIONS

The symptoms described by "electromagnetic hypersensitivity" sufferers can be severe and are sometimes disabling. However, it has proved difficult to show under blind conditions that exposure to EMF can trigger these symptoms. This suggests that "electromagnetic hypersensitivity" is unrelated to the presence of EMF, although more research into this phenomenon is required.

Psychological factors in postoperative fatigue

OBJECTIVE

To assess whether the fatigue commonly reported by patients following surgery is partly a result of somatization and/or cognitive-behavioral factors.

METHODS

One hundred eighty-three patients completed questionnaires before surgery and then 2 days, 3 weeks and 6 months afterward. Multiple regressions were used to assess which of the following factors were important in predicting self-reported postoperative fatigue, controlling for preoperative fatigue and for various demographic and surgical variables: negative mood, history of mood disorder, preoperative expectations of fatigue, preoperative worry or optimism about surgery, preoperative beliefs about the benefits of activity or rest, self-reported postoperative activity, self-reported cardiovascular deconditioning, and availability of social support.

RESULTS

Controlling for demographic and surgical variables and preoperative fatigue, postoperative fatigue showed significant associations with negative mood at each stage of follow-up (p < .001) and was significantly predicted by history of mood disorder at 2 days postoperatively (p = .02). Higher fatigue expectations were self-fulfilling at 3 weeks after surgery (p = .02), whereas preoperative belief in physical activity as being beneficial to recovery predicted reduced fatigue at 6 months (p < .001). Finally, self-reported breathlessness after exercise, an indicator of cardiovascular deconditioning, was also significantly associated with greater fatigue at 6 months (p = .02).

CONCLUSION

The results indicate that psychological processes may well be relevant in the etiology of postoperative fatigue. In particular, the results relating to mood and expectations suggest that somatization may be particularly important in the first few weeks following surgery, whereas cognitive-behavioral factors and cardiovascular deconditioning may be more important in determining later-stage recovery.

A systematic review and meta-analysis of the incidence and severity of postoperative fatigue

OBJECTIVE

Postoperative fatigue is common following major abdominal surgery. Less is known about its prevalence in other surgical subgroups, and about its long-term prognosis. A systematic review of prospective cohort studies was conducted to clarify these issues.

METHOD

Studies were identified from an extensive literature search. Overall estimates of pre- to postoperative change in fatigue severity and the incidence of clinically significant postoperative fatigue were calculated using meta-analyses.

RESULTS

Eighty-one cohorts were identified. Type of surgery was found to be a possible predictor of fatigue severity, with major abdominal, gynaecological, cardiac and minor surgery apparently associated with greater fatigue than orthopaedic surgery. Limited data were available regarding the long-term persistence of postoperative fatigue.

CONCLUSION

Postoperative fatigue appears to be an important problem following only certain forms of surgery. Why this is so remains unclear, and further work using better fatigue questionnaires is now required to confirm these differences.

Systematic review and meta-analysis of interventions for postoperative fatigue

BACKGROUND

Postoperative fatigue is common, even after uncomplicated operations. Various theories have been presented regarding its aetiology, each suggesting different possible interventions. The purpose of this review was to identify all studies that have assessed interventions for postoperative fatigue and to evaluate these interventions using meta-analytical techniques.

METHODS

Randomized controlled trials of interventions, identified from a systematic search of relevant databases, were evaluated according to standardized criteria and categorized according to intervention modality. Data relating to the efficacy of each intervention at four different postoperative time-points were collated and data synthesis by meta-analysis was performed.

RESULTS

Analgesia is effective in reducing fatigue immediately after operation. Perioperative administration of human growth hormone reduces fatigue between 8 and 30 days after abdominal surgery. Weaker evidence was found to suggest an influence of glucocorticoid administration and of surgical technique on fatigue in the first week after operation. No evidence was found to support the theory that psychosocial or nutritional interventions affect the symptom.

CONCLUSION

While the results demonstrate that improved analgesia can attenuate immediate postoperative fatigue in most patient groups, further research is needed to determine whether the efficacy of human growth hormone and glucocorticoids extends beyond abdominal surgery. The paucity of research into cognitive-behavioural, sleep and activity-based interventions also needs to be addressed.

Presumptive dirofilariasis in a pale-headed saki monkey (Pithecia pithecia)

A 6-yr-old male pale-headed saki monkey (Pithecia pithecia), born at the Dallas Zoo, reentered the collection in 1994 after it was housed for 4 yr in Rhode Island and 2 yr in Florida. The monkey tested negative for both Dirofilaria immitis microfilariae and D. immitis adult antigens (via commercially available tests) upon return. However, it tested positive for adult antigens 1 yr later, and additional testing, including ultrasonography, suggested a diagnosis of aberrant dirofilariasis. Relevant evidence of previous microfilaremia in pale-headed saki monkeys at the Dallas Zoo is reviewed. Dirofilaria immitis infection should be included in the differential diagnosis list for any nonhuman primate with cardiopulmonary disease wherever the parasite is enzootic.