The purpose of this study was to explore the clinical features of FPAs, based on their location of occurrence. This was accomplished by making comparisons among 5 groups of patients, classified by the place of their FPAs. These comparisons revealed differences among 7 descriptors (sex ratio, drinking status, smoking status, FPA symptom severity, SDS score, frequency of co-morbid AG, and degree of avoidance behavior) and 4 symptoms (sweating, chest pain, feeling dizzy, and fear of dying) associated with the FPA.
People who experienced their FPA in a public transit vehicle or while driving demonstrated a higher frequency of co-morbid AG and the highest degree of avoidance behavior; these results are in keeping with those of previous studies [10, 14–16, 18]. The present study also confirmed that the place of the FPA correlated to the development of AG. Of the patients diagnosed with PD and co-morbid AG, those who experienced their FPA at home more frequently experienced a fear of dying during their FPA and felt more distress than those in the group that experienced their FPA outside the home. Thus, the patients in these 2 groups are considered to have different clinical features.
A smaller proportion of people who experience their FPA at home subsequently developed AG. However, a significant proportion of individuals within this group (37%) still developed AG. The results show a similar frequency as has been reported in previous studies [10, 14–16, 18].
In this study, patients in the at-home group experienced a fear of dying more frequently than did patients in any other group. This finding suggests that fear of dying might be a characteristic symptom of people who experience their FPA at home. Vickers and McNally (2005)  reported that the fear of dying is the symptom that best distinguishes the panic attacks of individuals diagnosed with PD from those without PD. In their study, the fear of dying had the largest effect size, an association with PD that persisted after control for other symptoms, and a continued importance after multivariate analyses. Additionally, Segui et al.  reported that palpitations (86.7%), shortness of breath (76.5%), fear of dying (69.9%), and dizziness (63.6%) were the most frequent and intense symptoms reported by PD patients. Cox et al.  also reported that, of the DSM symptoms, fear of dying and tachycardia were the symptoms most often rated as very severe. The findings in the current study suggest that patients experiencing the most severe symptoms during their FPA were those who experienced that attack at home. The fact that the at-home group of patients experienced more severe symptoms during their FPA than did those in other groups, suggests that early interventional treatment of PD may be particularly important to the patients in the at-home group.
FPA symptoms and the location of the FPA
Other than fear of dying, significant differences were found for 3 other symptoms and were related to the location of the FPA. A higher proportion of patients in the driving and public transit groups experienced sweating. In clinical practice, many PA patients describe this symptom, including descriptions of experiences such as wet hands while driving. Some studies report that such autonomic occurrences may be a symptom subtype that is often mixed into other groups of physical symptoms.
Chest pain was a physical symptom experienced by a higher proportion of the patients who had their FPA while at school/office as well as by those in the at-home group. Lang et al.  reported that chest pain or discomfort occurred more often in cases of PD without AG. The school/office group and the at-home group had the lowest rate of AG, suggesting that the current results are consistent with those of the Lang et al.  report.
Feeling dizzy was reported by a higher proportion of the patients classified into the driving and outside home groups. Several studies have reported a relationship between feeling dizzy and AG. Yardley et al.  studied the prevalence of PD symptoms in a sample of patients experiencing dizziness and examined how this affects them psychosocially. Patients with panic-related dizziness were reported to have higher rates of vertigo and agoraphobic behavior when compared to those patients who had only panic or dizziness alone. Jacob et al.  reported that vestibular symptoms during panic spells are not necessarily related to the presence of vestibular dysfunctions that are objectively identifiable; nonetheless, patients with PD associated with AG have significantly more vestibular disorders than other patients. Vaillancourt and Bélanger  also reported that people suffering from both PD and dysfunctions of the equilibrium system might avoid activities that rely heavily upon good balance; such as walking on uneven surfaces or undertaking some forms of transportation. Thus, the driving group, as well as the outside-of-home group, which demonstrated higher rates of AG had been active outside of the home (e.g., walking on the street) in an adverse situation and experienced a higher frequency of feeling dizzy.
Other demographic characteristics also show significant differences when classified according to the reported place where the patient's FPA was experienced. The at-home group showed a high proportion of females, while the school/office and driving groups showed a high proportion of males. As might be expected, the place where a particular group of people spends the majority of their daily life influences this result (for example, there are many women who remain at home and a higher proportion of men who spend significant amounts of time driving and at work).
A higher proportion of people in the school/office, driving, and public transit groups reported alcohol consumption than in other groups. Interestingly, PD occurs at a higher rate among alcohol abusers [29, 30]. Craske et al.  found that the majority of their PD subjects reported only 1 life stressor and it was often related to ill-health or alcohol use.
A far higher proportion of subjects in the driving group were reported to be smokers. This group was also observed to have a higher proportion of men; therefore, there may be a relationship between male smokers and PD. Pohl et al.  reported that the prevalence of smoking was significantly higher in female PD patients than for control subjects (40% vs. 25%). However, smoking rates among males did not differ between PD patients and control subjects. Other studies have reported that patients with anxiety disorders have a greater propensity to be smokers [32, 33]. These inconsistencies suggest that further study regarding the association between smoking and AG are required.