Ambulatory Assessment

Introduction

Ambulatory assessment designates a new orientation in behavioural and psychophysiological assessment. This approach relates to everyday life (‘naturalistic’ observation) and claims the ecological validity of research findings. Methods of recording psychological data in everyday life have a long history in differential psychology and clinical psychology. Event recorders for the timed registration of stimuli and responses, ‘beeper’ studies in which a programmable wristwatch prompts the subject to respond to a questionnaire, self-ratings on diary cards, and electronic data loggers have all been used for this purpose. The arrival of pocket-sized (hand-held, palm-top) computers has eased the acquisition of data considerably. Computer-assisted methodologies facilitate investigations in real-life situations where relevant behaviour can be much more effectively studied than in the artificial environment of laboratory research. Such field studies are essential, for example, in research on stress-strain or in research on mechanisms that trigger off psychological and psychophysiological symptoms.

Ambulatory assessment originated from a number of previously rather independent research orientations with specific objectives. Clinical (bedside) monitoring was introduced as a means of continuously observing a patient's vital functions, e.g. respiratory and cardiovascular [Page 14]parameters under anaesthesia, during intensive care and in perinatal condition. If relevant changes occur, i.e. if certain critical values are exceeded, an alarm is set off. Biotelemetry employs transmitter-receiver systems (radio-telemetry) in order to measure physical functions in real life, e.g. cardiovascular changes during intense strain at the workplace or during athletic performance. Radio equipment basically makes two-sided communication possible, i.e. feedback, telestimulation and telecommand, in addition to telemetry. Ambulatory monitoring means continuous observation of free-moving subjects (patients) in everyday life as compared to stationary, bedside (‘wired’) monitoring. Ambulatory monitoring can be conducted either by biotelemetry or by a portable recording system. This methodology is appropriate for patients who exhibit significant pathological symptoms which, for a number of reasons, cannot be reliably detected in the physician's office or hospital as compared to a prolonged observation in everyday life. Such cases include ventricular arrhythmia, ischaemic episodes, sleep apnea, and epileptic seizures. Here, ambulatory monitoring furthers valid diagnoses as well as the stabilization of medication. Field research comprises observation in natural settings in contrast to the laboratory. Field research is an essential methodology in cultural anthropology, social research, and ethology. Likewise, in psychology and psychophysiology some research issues require field studies to obtain valid data (see Kerlinger & Lee, 2000; Patry, 1982). Behavioural assessment methods include, besides laboratory observation, a variety of in-vivo (in-situ) tests, simulated and quasi-naturalistic settings, such as behavioural approach/avoidance tests (BATs) which were designed to assess behaviour disorders and clinical symptoms.

Ambulatory assessment brings together those research orientations that correspond to each other in their basic ecological perspective. Ambulatory assessment involves the acquisition of psychological data and/or physiological measures in everyday life according to an explicit assessment strategy which relates data, theoretical constructs, and empirical criteria specific to the given research issue. Such field studies are not solely concerned with the ambulatory monitoring of patients, but rather include a wide spectrum of objectives and applications. Common features are: recordings in everyday life, computer-assisted methodology, attempts to minimize method-dependent reactivity, maintaining ecological validity and, therefore, outstanding practical utility for various objectives – such as monitoring and self-monitoring, screening, classification and selection, clinical diagnosis, and evaluation – in many areas of psychology and psychophysiology (de Vries, 1992; Fahrenberg & Myrtek, 1996, 2001a, 2001b; Littler, 1980; Miles & Broughton, 1990; Pawlik & Buse, 1982, 1996; Pickering, 1991; Suls & Martin, 1993).

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