Jan 20, 2012


The Time Machine electronic TV time monitor is part
of an intervention program designed to help reduce the amount of time children
spend watching television, and thus encourage them to participate in healthier
physical activities. By specifically regulating how long a child can watch the
television before the signal is interrupted, parents can use the device as one
component in their strategies to get children away from the TV screen and into
activities that will improve their physical health. An experimental evaluation
of the intervention found that although there were decreases in time spent
viewing TV and time spent in front of a screen, as well as slight increases in
physical activity, there were no statistically significant differences between
children in the group using the Time Machine and those in the control group.


Target population:
Children and their parents

The intervention program is designed around using an
electronic TV time monitor (The Time Machine by Family Safe Media) to regulate
the amount of time spent watching television. Along with decreasing the amount
of time children spend viewing TV, the program also aims to have positive
effects on habitual physical activity, snack food intake, and body mass index.
Participating families are provided with up to two TV monitors for their home
televisions. Time Machine restricts television access by controlling the TV
signal and interrupting it after an allotted time period to prevent any further
watching. Time is controlled by inserting tokens (worth 30 minutes of TV time)
into the Time Machine. An additional option exists for parents to have certain
blocks of time restricted, in order to regulate the types of programs viewable
by their children.

After hearing an explanation of the functions of the
device and suggested usage of the device to restrict TV viewing to an hour or
less per day, parents participate in a discussion about how to use the Time
Machine in their household. Each family is given 30 tokens, and parents have
access to the monitor so that tokens can be reused. Following installation of
the device, researchers and parents discuss ways to manage time spent watching
television (e.g., having TV free days, not watching TV during meals, or moving
the TV to a less accessible spot). The period for the intervention lasts 6
weeks. No further advice on how to regulate television watching is given to
participants after the initial session.

The Time Machine device can be purchased online for


Evaluated population: A total of 29 children participated in the study. Participants were recruited
through posted advertisements in the local community of Auckland, New Zealand.
To be included in the study, participants had to be between 9 and 12 years of
age and had to typically watch over 20 hours of TV per week. Families with
children under 3 were ineligible due to a choking hazard associated with pieces
of the Time Machine. Thirty-eight percent of the sample were female, and 65
percent were New Zealand European, 14 percent Maori, 14 percent Pacific, and 10
percent other. The average age of children in the sample was 10.4 years.

Approach: Participants were randomly assigned to either the Time Machine intervention
(N=15) or control (N=14) group. Parents in the control group received verbal
advice on general strategies for how to reduce TV viewing and, as with the
intervention group, this is the only time they received any assistance. There
were no significant differences in terms of demographics between groups at
baseline. However, while not statistically significant, children in the control
group watched fewer minutes of TV per week and had fewer screen time minutes per
week than the intervention group at baseline. Baseline television watching per
week was substantially lower than expected for both groups, which may indicate a
potential issue with self-reported data.

To measure the effectiveness of the program, data
were collected using self-report measures of time (minutes) spent watching TV
and the frequency and duration of physical activity and other sedentary
activities (e.g., reading, listening to music, playing video games, or using the
computer), before and after school (on the previous school day) and all day on
the previous Saturday. Data were also collected on daily snack intake and body
mass index. All measures were collected at baseline and at the 6-week
post-intervention follow-up. Participants also wore pedometers for seven
consecutive days at baseline and at the follow-up which provided an average
number of steps taken.

Results: Following the 6-week intervention, weekly TV viewing did decrease for the
intervention group, although there was no statistically significant difference
between groups. There was a decrease in self-reported total weekly screen time
for both groups, as well as slight increases for both groups in average daily
pedometer counts; however, a statistically significant difference did not exist
on either measure. The large decreases in time spent in-front of a screen did
not yield comparable increases in physical activity, which may have indicated a
self-reporting bias or that screen time was being replaced with other activities
that were sedentary. Children in the intervention group also decreased in total
snack energy intake, while children in the control group experienced no change;
however, this difference was not statistically significant. BMI also did not
significantly change in either group, but this was expected given the short
intervention period.




Mhurchu, C.N., Roberts, V., Maddison, R., Dorey, E.,
Jiang, Y., Jull, A., & Tin Tin, S. (2009). Effect of electronic time monitors on
children’s television watching: Pilot trial of a home-based intervention. Preventive Medicine, 49, 413-417.

Children, Adolescents, Males and Females (Co-Ed), Home-Based, Cost Information
is Available, Manual is Available, Parent or Family Component, Nutrition, Other
Physical Health

Program information last updated 1/20/12