Study Design
To evaluate the effectiveness of SAFEHIP hip protectors a quasi-experimental design will be
used to compare a control group to an intervention group.
Quasi-Experimental Design- Time Series Design with Comparison Group
E:
O1
O2 O3
O4 X
O5
O6
O7 O8
----------------------------------------------------------C:
O1
O2 O3
O4
-
O5
O6
O7 O8
Below is an assessment of the threats to validity to offer insight into the strengths and weakness
of this type of study design.
Threat
Testing
Explanation of the Extent of the Threat
Testing is an issue because the subjects will be given a pretest and a posttest to gauge feelings, ideas, and behaviors.
History
History should not be a threat because both groups are
experiencing time and external events similarly. The multiple
time series also allows for more data to be collected and
compared aiding in the analysis phase to reduce the risk of
this bias.
Instrumentation
Instrumentation should not be a threat because it will not
change during the study or differ between groups.
Maturation
Maturation should not be threat because both groups will
mature at similar if not identical rates.
Attrition
Attrition would need to be assessed at the end of the study to
evaluation whether or not participants of the study dropped
out or withdrew from the study due to a systematic reason
related to the variables.
Statistical Regression
Statistical regression might be an issue because the
participants will be chosen base on their resident status in a
nursing home. The fact that they no longer reside
independently might imply they have a higher risk of falling
(extreme behavior) and therefore are located in the extremes
of a normal distribution, which might affect their scores at
the end of the study and allow them to regress towards the
null
Selection
Selection bias is a big issue in this type of design. Due to the
nature of the intervention the study cannot feasibly be
conducted as a randomized trial. Selection into the control
and/or experimental group might be related to the dependent
variable producing biased results.
Contamination
Contamination should not be an issue in this study because
the intervention is worn by the participant on their body and
cannot be shared among residents.
Hawthorne Effect
The Hawthorne Effect could be an issue because the
participants will know they are participating in a study and
may be motivated to change their behaviors relating to their
risk of falling.
Chance
Chance is always a risk and should be statically assessed
when the results are being analyzed.
Data Collection
Data will be collected by nurse aids who check the position of the hip protectors twice a day and
record any issues, the research assistances to administer the pre-test, posttest and weekly process
evaluations, and through medical records provided by the participants PCPs.
Study Participants
The control and experimental groups will be recruited from the same nursing home in Watham,
MA by way of their primary care physician. Recruitment of the experimental group will be
initiated by a referral by their physician to participate in this study. The physician will explain
the risks and benefits of participating in the study and explain the purpose such a study. After the
patient agrees to be contacted by the Principle Investigator, a formal referral form will be sent to
the PI and the PI will contact the potential participant. The control group will be selected among
the remaining residents with in the nursing home by simple random sampling. The referral
system, as well as the partnership of the nursing home will allow access (given resident’s
consent) to medical and behavioral records that would have otherwise been unavailable to
researchers and facilitate the recruitment process.
The inclusion and exclusion criteria for participation are listed below.
Inclusion
Exclusion
Has resided in the nursing home for more than
Lives independently or has lived independently
6 months
in the last six months
Has fallen one time in the last 6 months (no
Has been diagnosed or treated for a mental
more, no less)
illness in the last 6 months
Has a permanent PCP
Is not currently able to represent themselves as
their own guardian
Agrees to the terms of the study and the data
Has been admitted to the hospital for any
collection protocol
reason other than an incident related to falling
in the last 6 months
Is approved by their primary care physician to
Is unable to read, write or audibly understand
participate in this study
English or Spanish
Is able to mobilize with 80% independence
Has mobility issues unrelated to a recent fall
Independent Variables:

Use of SAFEHIP hip protectors
SAFEHIP:
SAFEHIP hip protectors are made for people, more specifically the elderly, to provide
safe, confortable and effective hip protection in the event of a fall. Designed for individuals who
have had, or are at risk of falling, SAFEHIP helps to reduce the incidence of hip fractures by
shunting energy away from the hip area upon impact during a fall. The horseshoe-shaped shield
disperses energy away from the hip and reducing the amount of energy absorbed by the grater
trochanter which reduces the risk of hip fractures.
SAFEHIP is made from a textile material called spacer fabric technology that allows this
hip protector to be cooler in temperature than other hip protectors because of its ability to
transport the moisture and heat away from the skin which aids in the comfort and effectiveness
of this particular brand. SAFEHIP hip protectors are inserted into briefs that are available in sizes
XS to XXL and are said to be dry and confortable, which minimizes reddening and itching and
promotes wear-ability.
There are three different types of hip protectors. SAFEHIP falls under the category that
can be described as underwear with sewn-in hip protectors. Another category can be described as
underwear with pockets that hold removable protectors, and the last category of hip protectors,
are belts worn on the outside of the clothing with hip protectors attached. For this study the
SAFEHIP hip protector is advantageous because the horse-shoe shields are sewn in and once the
brief is put on by the study participant, the shields are more likely to be in the correct position
and worn more consistently throughout the day.
Compliance:
Study participants in the experimental groups will wear the hip protectors as instructed by
the manufacturer every day during awake hours for eight weeks. The briefs and shields will be
inspected by the nurse aid twice daily during her normal rounds to ensure proper placement. The
aid will record data after each check. Participants will wear only the SAFEHIP brand of hip
protectors.
Mediating Variables: These variables will be collected to help understand the relationship
between the hip protectors and the incidents of hip fractures

Perceived level of self-efficacy measured with the General Self- Efficacy Scale (GSES)
developed by Matthias Jerusalem and Ralf Schwarzer

Internal locus of control measured with the Locus of Control Test developed by Rotter

Family involvement measured with the pre-study questionnaire

Level of mobility measured with the pre-test questionnaire
Moderating Variables: These variables will be collected to help understand the relationship
between the hip protectors and the incidents of hip fractures

Participant’s gender will be determined by medical records

Participant’s race will be determined by medical records

Participant’s ethnicity will be determined by medical records

Participants’ former profession ( to evaluate class) will be determined by the pre-study
survey
Dependent Variables:

Incidence rate of hip fractures will be measured by medical records

Fear of Falling will be measured with the Falls Efficacy Scale-International (FES-I)
developed by members of the Prevention of Falls Network Europe

Mobility will be measured by the Elderly Mobility Scale

Psychosocial Status will be measured by the Geriatric Depression Scale in addition to the
psychosocial screening tool the nursing home currently uses.