Our study indicates that patients with vertigo or dizziness consider many different aspects of functioning and health as relevant. Aspects from the component Activities and Participation were most prominently captured, followed by aspects covering Body Functions. Various environmental and personal factors contributed to the multifaceted picture of functioning in vertigo. In our study the ICF turned out to be a useful tool to code various impairments and restrictions caused by vertigo and dizziness and to describe disease specific functioning and quality of life since the majority of concepts in patients’ statements could be linked to the ICF.
Regarding the ICF component Body Functions participants reported, apart from obvious aspects (e.g. sensations associated with hearing and vestibular functions), orientation, temperament and personality functions, confidence, motivation, emotion, sleep, appetite and exercise tolerance as relevant. It is commonly recognized that vertigo has considerable impact on quality of life, but the distinct components are often unclear. Generic instruments such as the SF-36  give but a very general picture of impairment of mental functions. Anxiety and avoidance have been reported as psychological consequences of vertigo [1, 27]. Also, emotional problems seem to be associated with vertigo . Depression and somatization as well as increased obsessive-compulsive attitude have been observed .
“(…) It really gets me down.”
(b152 Emotional functions, Pt. 6)"
„Okay, just from the beginning, I wanted to be left alone (…) I didn’t want to go anywhere (…) And when I got such panic attacks … nervous break down… because I don’t want to go outside (…).
(b152 Emotional functions Pt. 009)"
“And at night it is like…sleeping properly… does not work any more.”
(b134 Sleeping functions, Pt. 001)"
Of the ICF component Activities and Participation, 62 categories were mentioned as relevant in our study. This underlines how much the pathology interferes with daily life. The reported categories ranged from very basic activities such as watching, listening and reading to more complex items such as managing daily routine, using transportation, self-care and housework:
“When things pass by quickly… This is what you have to avoid and you actually do avoid… Just like watching TV. I haven’t been watching TV since December.”
(d110 Watching, Pt. 001)"
“I really loved reading. At the moment I can’t really read, because I get dizzy after a little while.”
(d166 Reading, Pt. 009)"
“When you want to go by bus, you have to take a rest at the bus stop…and then you have to get in the bus fast. And you have to get out fast and again… have a rest at the bus stop. Everything gets more complicated.”
(d4702 Using public motorized transportation, Pt. 011)"
“And I am happy to reach the toilet [without a vertigo attack]”
(d530 Toiletting, Pt. 012)"
“It’s worst when I have to do homework, for example when I have to hang curtains…”
(d6402 Cleaning living areas, Pt. 008)"
It is obvious that all movements and body positions that are likely to provoke attacks were reported as restricted.
„As soon as I was standing up… upright… [vertigo attacks occurred]… then walking was really hard (…).“
(d4104 Standing, Pt. 006)"
Almost all aspects of social participation were perceived as restricted, namely personal and formal relationships, employment, leisure, sports and community life. This is in line with the work of Neuhauser and colleges who showed in a large, community based study that up to 20% of individuals with vertigo avoid leaving the house . Dizziness is known to impede activities of daily life  and to interfere with workplace activities . Because attacks of vertigo are mostly uncontrollable and unpredictable, many patients suffer from the mere anticipation of the attack  which may be as restricting as the pathology itself .
„Okay…but… now there is the vertigo (…) when I am standing in front of my customers, or employees… swaying… That doesn’t work!”
(d730 Relating with strangers, d7401 Relating with subordinates, Pt. 009)"
„[At work] I have to prepare these trolley tables all the time. Ist a permanent.. standing, bending, preparing… arround these trolleys… Then bringing them allover the building… four stories… I can’t imagine that I could handle this at the moment.”
(d850 remunerative employment, Pt. 001)"
“I would prefer going to work. But my ENT-doctor says that it’s too risky because of the spells… vomiting, high blood pressure, panic attacks,…”
(d850 Remunerative employment, Pt. 001)"
Environmental Factors were reported as interfering and interacting with functioning. Among those were factors of the natural and built environment such as sounds, vibrations, climate, temperature, population density and architectural design. To give an example, paroxysmal positioning vertigo is suspected to be associated with temperature variation and air pollution .
„Yes…, in daily life… crowdy places… where a lot of people… and noisy…This is what I cannot tolerate at the moment.”
(e2500 Sound intensity, e2151 Population density, Pt. 001)"
„And as I’ve said before, when I’m walking, strolling in the sun, I feel that the vertigo is even more extreme.”
(e225 Climate, Pt. 008)"
Likewise, family, friends, neighbors, colleagues and their attitudes were reported as relevant environmental factors. They can act as facilitators or barriers for the individual affected by vertigo, since vertigo may change social roles and behaviors, also towards others .
“I have two daughters. They give me a lot of support. And my husband.”
(e310 Immediate family, Pt. 001)"
„They, the people next to me, or acquaintances, too… When we went out for diner or to cinema… They knew that I suffer from vertigo attacks and that gave me the freedom… when I recognized: Oh! There is.... Then I could call them to help me: „Bring me to my car“(…).”
(e420 Individual attitudes of friends, Pt. 012)"
In general, the ICF turned out to be a useful tool to describe the situation, determinants and consequences of vertigo. Only few concepts reported by the patients could not be coded with ICF categories. Most of them were related to personal factors, mostly coping strategies. As an example, some patients reported to visit only places which are save if a vertigo attack occurs, such as buildings that have staircases with handlebars, or places where they can lay down during a vertigo attack. Other patients reported to schedule trips or shopping more carefully. Coping strategies and resilience are reported in the literature as major determinants of symptom severity .
It was not the intention of our study to draw generalizing conclusions on experiences towards functioning and health of vertigo patients, or to report impact in various subgroups, or to compare them amongst others. We did include patients with different types of diagnoses in our study to ensure covering the widest range of experiences. The qualitative approach should always be the primary method to get a first idea about relevant aspects of functioning. As in quantitative studies, validity of this largely depends on the choice of participants. Participants should represent the typical range for which subsequent studies should be representative. The results of our study should provide a first selection of patient-relevant items which have to prove its validity in terms of frequency and discrimination before being implemented in further applications, such as future studies or clinical issues.
Some limitations have to be mentioned. On the one side, selection of patients for the interviews might be biased towards individuals with milder disease who are capable to undergo an interview procedure. On the other side, patients seen in a specialized tertiary care dizziness clinic may be selected towards those with more severe symptoms or more chronic conditions. However, our findings have high face validity and are in line with the studies conducted in this field.
Altogether, our study gives a first impression from the patients' perspective using the ICF regardless of potential selection bias.