Introduction

Non-traumatic headache episodes are a common presenting complaint at emergency departments worldwide [1]. Intracranial pathology is found in only a minority of the patients, and it is therefore believed that most of the ED visits represent primary headache disorders [2].

Many intrinsic precipitating factors for headache episodes in susceptible individuals were reported [3–8]: afferent stimulation, physical activity, menstrual changes, psychological factors, sleep cycle disorders, and dietary factors, yet none of them can fully account for the variability in the frequency of ED headache related visits. Extrinsic factors such as climate patterns and ambient air pollution was previously reported to be associated with changes in daily headache related ED visits as well [9].

Patients, with both tension and migraine type headaches, often report stress to be one of their major triggers [4, 10]. Although stress is a universal experience, it is difficult to measure the personal level of stress, and it is almost impossible to quantify the level of collective stress, experienced by groups or communities.

A potential source of stress may be the news, particularly bad news. According to Affective Intelligence—AI [11], anxious individuals are motivated to be information seekers, as information may be vital to their own survival. Hence, it is not surprising, that while individuals state they do not appreciate negative news, we witness a tendency to seek such news [12].

News watching in itself might elevate anxiety. A study from the USA where self-reported data was collected, suggested that following the news was one of the biggest daily stressors among individuals who report a high level of stress [13]. Moreover, a recent internet-based survey following the Boston Marathon bombing showed that repeated bombing-related media exposure was associated with higher acute stress than was direct exposure (presence in the bombing area). In addition, watching a 15-minute news segment was enough to trigger persisting negative psychological feelings, which decreased only after a progressive relaxation [14].

In this ecological population based study we sought to evaluate the association between the daily national news consumption and their content with headache related ED visits.

Materials and methods

Results

The study population comprised 14,010 patients with 16,693 ED visits, with 19.1% of the patients having more than one visit during the study decade. Among them, 57.6% female and 54.3% were younger than 40 years old (Table 1). Mean, median, minimum and maximum daily television rating percentages (the percent of potential viewers who watched the evening news) of all three major news channels during the study period were the following; 29.3±5.2, 29.5, 3 and 51.0, respectively.

Table 1

Frequency of ED visits for headache (2002–2012).

Total Number of Headache ED visits	16,693
Age (years), mean ± SD	41.3 ±18.6
<40, n (%)	9,067 (54.3%)
40–60, n (%)	4,608 (27.6%)
>60, n (%)	3,018 (18.1%)
Gender
Female, n (%)	9,616 (57.6%)
Number of visits per patients, median (Range)	1 (1–31)

Effect of daily news rating on the incidence of headache ED visits

An increase of 5% in daily rating was associated with increase in ED visits the following day, relative risk (RR) = 1.017, (95% CI 1.001–1.033). (Fig 1) but not two and three days after, RR = 0.953(95% CI 0.939–0.967) and RR = 0.990 (95% CI 0.973–1.007), respectively, where the association was protective. This association increased with the age of the patients; RR = 1.119, (95% CI 1.075–1.65) for older than 60-year-old, RR = 1.044 (95% CI 1.010–1.078) for ages 40–60 and RR = 1.000 (95% CI 0.977–1.023) for younger than 40-year-old. In addition, we observed a marginal increase in the effect among female patients, RR = 1.04 (95% CI 1.020–1.068) as compared to men, RR = 1.015 (95% CI 0.990–1.042). The non-linear association between rating estimation the following day and ED visits with headache was expressed as LOESS curve scatter plot (S1 Fig).

Fig 1

Relative Risk (RR) for daily ED visits for headache associated with daily rating percent, among age groups and by male and females.

Relative Risk (RR) and 95% Confidence Interval for ED visits per increase in 5 units of daily rating percentages. Results of the separated Poisson regression models, for study period 2002–2012, adjusted for public holidays.

Similar to the linear analysis, the magnitude of effects observed was larger among older patients. We further examined whether two days of cumulative exposure to high percentage of rating estimates (above 29.5%—median rating percentage) is associated with an additional increase in risk of ED admission. This effect was found only among older patients (over the age of 60); RR = 1.275 (1.172–1.387) (Table 2).

Table 2

Relative Risk (RR) for daily ED visits for headache associated with cumulative exposure over 29.5%* percent in two days preceding the ED visit.

	RR**	95%CI
All	0.990	0.952–1.030
Age >60	1.275	1.172–1.387
Age 40–60	1.039	0.967–1.116
Age <40	0.884	0.839–0.933
Male	0.958	0.905–1.015
Female	1.019	0.968–1.072

Discussion

In this analysis of more than fifteen thousand headache related ED visits over a decade, we attempted to assess the short term effects of Israeli national news consumption. We demonstrated an association between news consumption and the incidence of headache related ED visits (during the following day. This association was particularly pronounced in patients over 60 years of age. This effect was not related to the content of the news headlines.

Stress is a well-recognized headache trigger, in both migraine and tension type headache. Recently, in a longitudinal study [18] self-report of stress was associated with the frequency of both migraine and tension type headache (an increase of 10 points in stress intensity measured by VAS 0–100 was associated with an increase of 6.0% of TTH frequency and 4.3% for migraine). The effect was higher in younger age groups. Increased headache prevalence was also reported among survivors and responders following major natural or man-made disasters [19, 20].

While stress is a subjective experience affected by multiple biological, psychological and social factors, collective community wide experiences may affect the personal level of stress. The effect of such collective experiences is usually referred to as collective stress [21].

During major national or international crises, the public seeks information. This public attention, which elevates news consumption, may be indicative of increased stress levels. In this sense, the level of news exposure, gauged by television news ratings, can be perceived as a surrogate marker of increased collective stress. On the other hand, widespread media coverage transmits the impact of stressful events to populations not exposed to the event itself, amplifying collective stress and psychological trauma related symptoms. Such effect was demonstrated in several major events and disasters such as the Oklahoma City bombing [22], H1N1 influenza pandemic [23], 1994 California earthquake [24], Boston Marathon bombing [14], the 1990 Gulf War [25], and 9/11 [26]. Therefore, news consumption is not only a marker of collective stress, it is also a collective stress amplifier, contributing by itself to the stress and its effect.

Two mechanisms may explain the association between the collective stress and increased rates of headache associated ED visits. The first is a psychobiological effect, according to which, collective stress is a headache-precipitating factor similar to personal stress, possibly increasing the likelihood of headaches or their severity, resulting in increased rates of ED consultations. The second is a psychosocial effect, increasing the tendency of headache sufferers and their caregivers to seek emergency medical support for headache episodes during high collective stress events.

While the association between personal stress and different types of headaches was especially pronounced in young individuals, in our study, the association was the greatest among individuals older than 60 and had a marginal increase in the effect among female patients. Since TV news exposure is largely influenced by age, with higher exposure rates in the elderly population [27], it is possible that news viewing rates best reflect (or amplify) collective stress levels among older age groups, and not among younger individuals which mostly consume news from new media rather than television. It is also possible that elderly individuals with smaller support networks have a higher tendency to seek emergency medical assistance in high collective stress situations. Moreover, it was suggested that women suffer more stress than men and their coping style is more emotion-focused compared to men [28].

Our study has several important limitations. First, our study does not allow conclusions about the interaction between media consumption, collective stress and headaches. Moreover, Israel is unique in its continuing stressful events lifestyle and its media consumption style, therefore making the generalization of the results to other countries and communities difficult [29]. The nature of the data does not allow differentiating potential differences between TTH and migraine. Lastly, the ecological nature of our study does not allow for the individual assessment of news exposure.

The association of media consumption and headache morbidity should be further studied in different communities and setups. Prospective assessment of this association may provide us with new insights on the association between headache suffering and collective stress and possibly provide us with another possibly modifiable headache trigger.