Rosekind, M. R., Smith, R. M., Gregory, K. B., Miller, D. L. (1996). NASA Airlog: In Electronic Sleep/Wake Diary. Sleep Research, 25, 525.
Subjective self-report data on sleep/wake and related variables
are a core component of most sleep and circadian research and clinical activities.
The format for such data can range from individual analog scales to sleep/wake
diaries to extensive clinical screening questionnaires. The NASA Ames Fatigue
Countermeasures Program examines fatigue, sleep loss, and circadian disruption
during flight operations and in other operational settings. For almost 10
years, the Program utilized a Pilot's Daily Log to collect subjective report
data from flight crews in a variety of operational studies. This Log was
used to collect data on the duty day, sleep/wake variables, meals, caffeine
use, mood, and other activities (e.g., exercise). Pilot volunteers would
carry the Log in their pocket and collect data prior to, during, and following
a trip schedule. The Logbook data was then entered into a database for subsequent
analysis. The paper and pencil Logbook required 5 hrs to input data, extensive
deciphering of handwriting, and has the standard drawbacks of subjective
data.
The NASA Ames Fatigue Countermeasures Program has developed
the NASA AIRLOG (Ames Interactive Reporting LOG), an electronic sleep/wake
diary to collect subjective data in operational settings. The objectives
were to develop a system for easy and rapid data entry, increased question/input
capacity, fast download and data transfer mechanism, and production of initial
data analysis. The AIRLOG was developed with off-the-shelf technology to
facilitate access and reduce development costs and time. The AIRLOG consists
of a Sharp Wizard (Model OZ-7000/8000 series) (1) utilizing a Logix Data
Collection Card (128KB EPROM and 32KB RAM) (2). The diary questions are
created using a Survey Generator run on a PC using a DOS 5.0 text editor.
Logix provides a Survey Generator and Data Collection Card User Manual that
provides the question format and capabilities. The format allows for multiple
choice, true/false, numerical answers, and fill-in questions. Specific question
categories with subsets and mandatory questions can be defined. Once created
with the Survey Generator, the questions are downloaded to the Data Collection
Card for use in the Wizard. The menu driven diary can then be accessed and
completed by a subject at any time during data collection. An internal time
and date stamp provides information as to when data were actually entered.
Total cost for one AIRLOG system, with all required components, is about
$1,400 and approximately $600 for 10 systems.
The initial AIRLOG questions incorporated the previous
Pilot's Daily Log information and was expanded to collect increased subjective
data. The AIRLOG currently collects 215 questions in multiple choice or
fill-in-the-blank format (time entry or scaled answer). Memory capacity
allowed for up to 30 days of data collection with this number of questions.
It took about one month for a knowledgable individual to write and test
the complex structure of questions. After data collection, the information
is downloaded to a PC and imported into EXCEL for Windows, then processed
with a macro, and initial analyses printed out (preliminary means and standard
deviations for important variables and graphics). This entire process takes
approximately 5 minutes. Individual raw data files are then moved to a mainframe
(Vax 580) for more complete statistical analysis and incorporation into
a larger data set with physiological, performance, behavioral, and environmental
variables.
Prior to field use by flight crew, a user-friendly manual
was developed and a 12-min. video explaining the AIRLOG procedures for data
collection. A package that included the AIRLOG, manual, video, and actigraph
was sent to flight crew at least 3 days prior to scheduled departure. The
NASA AIRLOG has now been field tested in 4 studies across different aviation
environments. Nineteen flight crew collected 190 days of AIRLOG data in
a study examining the quantity and quality of sleep obtained in onboard
crew rest facilities on B747-400 aircraft. Twenty-one flight crew collected
126 days of data in a parallel study in B747-200 and 767 aircraft. Three
flight crew collected 30 days of data during a corporate aviation operation.
Six military flight crew collected 84 days of data during a mission. This
represents 49 flight crew collecting AIRLOG data over 430 days of field
operations. All data actually entered into the AIRLOG during any of the
field tests was complete.
The NASA AIRLOG is an electronic sleep/wake diary that offers a flexible platform for collecting subjective data. All of the initial AIRLOG objectives were met with the current system, including an increased data capacity, easy data entry, and 5 min. for download and initial analyses. In the initial field tests, the AIRLOG was well accepted by flight crews, functioned in a variety of flight operations around the world, and provided excellent data quality. The AIRLOG is easily modified and can therefore be used in any study requiring subjective data collection.
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(1) Sharp Electronics Corporation, Sharp Plaza, Hahwah, New Jersey 07430-2135
(2) Logix, Inc., 98 Ford Road, Denville, New Jersey 07834