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Poisoning Interventions
Child-Resistant Packaging and the Posion Prevention
Packaging Act
Background
The Unites States Poison Prevention Packaging
Act (PPPA) of 1970 was enacted to prevent young children from accidentally ingesting
hazardous substances ordinarily stored about the house. The law requires toxic,
corrosive, or irritative substances to be packaged in such a way that it will be
difficult for children less than 5 years to open them, yet not difficult for adults
to open. The first product to fall under this law was aspirin, on August 8, 1972,
with the law gradually encompassing more and more hazardous substances, including
some prescriptions and over-the-counter medications. Essential in the law’s
success is not only preventing children from opening child-resistant containers
but also permitting adults easy access to the medication. This may be especially
difficult to achieve among, for example, elderly persons or those with severe arthritis.
As a result, child-resistant packaging may be declined upon request at pharmacies,
thus increasing the risk of childhood poisoning among, for example, children who
visit their grandparents, who may not realize the need for such packaging when children
are no longer present in the household.
In other countries, there are different regulations
governing use of child-resistant packaging. In the US, many substances are individually
sold in child-resistant packaging, even if not required by law.
Here, we review studies on the effectiveness
of child-resistant packaging, both those required by law and those done voluntarily.
These interventions usually examine changes in incidence rates of poisoning before
and after the effective date of the law, which is different depending upon the hazardous
substance, but they can also examine the compliance rates of pharmacies in assessing
effectiveness. Other outcomes include mortality and morbidity culled from hospital
admissions and emergency room visits, calls to local poison centers, and national
databases. Finally, studies can also look at the ability of these devices to actually
deter opening by children, while maintaining easy access to adults.
Review of legislative
intervention studies:
Author | Dole et al., 1986 |
Study design and target population | Randomized controlled trial
Retail, licensed pharmacies in Memphis, TN.
(n=60) |
Intervention | Poison Prevention Packaging Act (PPPA) of 1970 and
its ability to force compliance from pharmacies. |
Outcomes | Number of pharmacies dispensing prescriptions in child-resistant
packaging per the PPPA.
Each pharmacy tested twice: once with conventional
prescription and once with experimental prescription that included statement,
"dispense in child-resistant container." |
Results | Of conventional prescriptions, 77% of pharmacies filled
prescriptions in child-resistant packaging.
75% of pharmacies complied with experimental
prescription. |
Study quality and conclusions | Simple yet effective study in evaluating pharmacy compliance
to the PPPA of 1970.
Only 60 of 100 pharmacies were eligible for
study. Even so, the compliance rates should be increased.
Better compliance with PPPA might reasonably
lead to decline in poisoning morbidity and mortality. Public disclosure of
compliance rates, legal interventions, and educational programs (directed
particularly to pharmacies) suggested as means to this end. |
Author | Walton, 1982 |
Study design and target population | Interrupted time series study
Reported accidental ingestions among children
less than 5 years, from National Electronic Injury Surveillance System (NEISS)
and National Center for Health Statistics (NCHS) between 1973 and 1978. |
Intervention | Poison Prevention Packaging Act (PPPA). |
Outcomes | Observed and expected annual accidental ingestion rates
resulting in ER treatment.
Death rates from poisoning.
Incidence rates adjusted for changes
in age distribution and changes in reporting levels in NEISS. |
Results | Overall ingestion rate for regulated products decreased
significantly from 5.7/1000 children in 1973 to 3.4/1000 children in 1978 (p<0.05).
Death rates from poisoning decreased from 0.9/1000
to 0.5/1000 over the same period.
Total estimated poisonings prevented
between 1973 and 1978 is 193,750. |
Study quality and conclusions | Good study using (underestimated) data from NEISS and
NCHS.
Study examined years in which most of PPPA effects
had taken place.
Estimated observed poisoning incidences
significantly underestimated; PPPA’s effect probably greater than reported. |
Author | Clarke and Walton, 1979 |
Study design and target population | Interrupted time series study
Reported accidental ingestions among children
less than 5 years in United States between 1965 and 1974. |
Intervention | Poison Prevention Packaging Act (PPPA). |
Outcomes | Annual incidence of accidental poisonings, reported
by Poison Control Centers and National Center for Health Statistics, adjusted
for change in age distribution, demand for aspirin, and other, non-packaging
related interventions.
Poisonings categorized into aspirin (baby
and adult) and non-aspirin poisonings. |
Results | Adjusted incidence of baby aspirin poisoning declined
overall from 1965 to 1974. Decline in pre-PPPA years (1965-1969) averages about
4%, while post-PPPA declines average about 32% each year.
Reduction in accidental ingestion of baby
aspirin of about 50%. Reduction of about 42% for regular aspirin.
Overall decrease of baby aspirin poisoning
by about 70% from 1969 to 1972.
Death rate (per million children) drops
from 3.4 in 1968 to 1.5 in 1974. |
Study quality and conclusions | Good general estimate of PPPA’s effect, despite
the fact that reporting by Poison Control Centers is voluntary.
Applications of PPPA for nonbaby aspirin products
took place around August, 1972.
Rates over years were adjusted for
population change, exposure change, and non-packaging related interventions. |
Review of child-resistant
packaging intervention studies:
Author | Rodgers, 1996 |
Study design and target population | Interrupted time series design.
Annual mortality rates from prescription drug
poisonings among children under 5 (NCHS data) from 1964 through 1992. |
Intervention | Child-resistant packaging. |
Outcomes | Annual mortality rates among children under 5.
Post-intervention period is 1974 through 1992. |
Results | Mortality rate ratio pre-intervention compared to post-intervention
= 2.01 (1.80-2.24).
Mortality rate declined significantly by approximately
1.40 deaths per million children under 5 after introduction of child-resistant
packaging. |
Study quality and conclusions | Good study showing reduction in mortality due to poisonings.
Reduction estimates are adjusted for trend (decline)
in unintentional injury deaths for all causes to children under 5, as well
as other covariates (improvement in ER care, heightened parental awareness,
etc.).
Substantial number of poisonings post-intervention
involved (1) improperly-secured caps and (2) products exempt from PPPA under
certain circumstances. |
Author | Assargaard and Sjoberg, 1995 |
Study design and target population | Before-after design
All childhood incidents reported to the Swedish
Poison Information Centre (GIC) during June through August, 1991 and 1992. |
Intervention | Child-resistant packaging (introduced in summer of
1992). |
Outcomes | Number of calls to GIC during summer of 1991 (before
interventions) and summer of 1992 (start of intervention) concerning accidental
overdoses of paracetamol among children. |
Results | Calls to GIC fell from 90 (before intervention) to
28 (after intervention). Eight of 28 calls made in 1992 were a result of use
of the old style of bottle.
Relative risk of accidental poisoning
in 1991 compared to 1992 (safety packaging) = 3.1
Children 2-3 years (primarily boys)
predominated incidents during entire study period. |
Study quality and conclusions | Decent study showing that child-resistant packaging
probably led to most of decrease in accidental overdoses among children.
Sales of liquid paracetamol prescriptions
were comparable between 1991 and 1992. Likewise, number of calls made to GIC
(for any reason) during these years were similar.
Exact magnitude of causal effect of
intervention uncertain; perhaps some reduction in calls due to better prevention
among families calling in 1991 (?). More data points both before and after
intervention needed. |
Author | Lawson et al., 1983 |
Study design and target population | Interrupted time series study
All children under 15 admitted to hospital
in Newcastle upon Tyne between 1974 and 1981 for poisoning (n=1720). |
Intervention | Child-resistant packaging for salicylates and paracetamol
only (introduced in January 1976). |
Outcomes | Hospital admissions with a diagnosis of poisoning before
and after intervention. |
Results | Among children under 5, poisoning from salicylate fell
from 34 in 1975 (before) to 11 in 1976 (after). No trend seen among paracetamol
poisonings, although numbers very small.
No further reductions among other poisonings (e.g.,
antidepressants and benzodiazepines) seen in subsequent 5 years. |
Study quality and conclusions | Intervention shows strong effect on salicylate poisonings.
Reason for non-significant result among paracetamol
poisonings may be due to small numbers and the fact that symptoms are difficult
to detect.
Packaging should be expanded to include
all medicines. |
Author | Howes (CPSC), 1978 |
Study design and target population | Non-equivalent control group design.
National Electronic Injury Surveillance
System (NEISS) ER-treated poisonings to children under 5, from 1973-1976. |
Intervention | Child-resistant packaging. |
Outcomes | Emergency-room treated poisonings before and after
introduction of child-resistant packaging. |
Results | Prescription drug poisonings treated in emergency rooms
decreased about 25% from 1974 to 1975 (p<0.01). Non-prescriptions drugs declined
18% in 1974, compared to 1973 (p<0.05). |
Study quality and conclusions | Good evidence for effectiveness of child-resistant
packaging (injuries among unregulated products increased during study period).
Best estimate of overall effect of intervention
is 35% reduction in ER-treated poisonings.
More direct assessment of intervention
needed. |
Author | Sibert et al., 1977 |
Study design and target population | Interrupted time series study
Children under 5 admitted to hospitals for
aspirin poisoning in South Glamorgan and Newcastle-upon-Tyne, UK, from 1974
through 1976. |
Intervention | Child-resistant packaging.
(Legislation requiring this packaging began
1/1/76--should we include this in the legislation section instead?) |
Outcomes | Hospital admissions for poisoning. |
Results | Admissions for aspirin poisoning fell by 63% from 1975
(n=129) to 1976 (n=48), p<0.001. |
Study quality and conclusions | No evidence for change in hospital admission policy
between years; change probably genuine.
Child-resistant packaging seems to be very
effective in reducing admissions for children under five. |
Author | Done et al., 1971 |
Study design and target population | Randomized controlled trial (crossover design, in which
subject receives every treatment in random order)
Children between 2 and 5 years (n=229) from one public
and six private nursery schools in Salt Lake Valley, Utah. |
Intervention | Child-resistant packaging (seven different types, including
screw-cap, snap-cap, and press-release packaging).
Three different testing sessions over three months,
utilizing different child-resistant packagings. |
Outcomes | Percentage of children able to open packaging within
10 minutes; number of "tablets" (candy) ingested.
Note: no overt instruction was given to the
children to open the packages; bottles were simply placed on their desks before
play time began. |
Results | Screw-cap packaging least effective in preventing child
access (93% children opened bottle and digested contents within 5 minutes).
Snap-caps were removed between 57% and 89% of time.
Pressure-release caps were most effective,
with removal percentages between 36% and 23%. |
Study quality and conclusions | Decent study comparing types of child-resistant packaging,
although extrapolating results to children below age 2 may be specious.
Different types of similar packaging (e.g.,
2 types of screw-cap packaging) were not compared within testing sessions.
Many children were able to open bottles
simply by striking it against desk; high-impact plastic needed to thwart these
efforts. |
Author | Lane et al., 1971 |
Study design and target population | Non-equivalent control group design.
Out-patients in one New York City municipal
hospital over a 22 day period in summer, 1969 (n=134). |
Intervention | Palm-n’-turn child-resistant packaging among intervention
group; ordinary packaging among control group. |
Outcomes | Compliance (of patients) with child-resistant packaging.
Percentage of adults able to open child-resistant medicines. |
Results | No significant difference in percentage of patients
who could open child-resistant packaging (87%) and control group (95%).
Compliance among intervention group was significantly
poorer than control group by Wilcoxon rank test (data not presented). |
Study quality and conclusions | Only half of the original study population followed
up.
Conclusions drawn from this study are shaky at best.
Indigent nature of subjects makes extrapolation difficult. |
Summary of legislative and child-resistant packaging studies
There was only one randomized controlled
trial to examine the PPPA’s effect on packaging of medications, showing that
about 75% of pharmacies in a certain region of the United States were compliant
with the (then new) legislation. The two remaining studies show clear declines in
poisonings after the passing of the PPPA in 1970. The effective date of the PPPA
varies according to the drug dispensed; this decline in poisonings persists well
after the PPPA was passed.
More recent studies of the effectiveness
of child-resistant packaging have showed that this intervention significantly reduces
the morbidity and mortality of childhood poisonings. In fact, the study by Rodgers4 revealed that a substantial number of the post-intervention
poisonings (as high as 40%) were due to either improperly-secured safety caps or
products that were not required to be packaged in a child-resistant container. Studies
that were conducted before most medications were required to be placed in child-resistant
packaging showed a clear decline in poisonings among children under five. While
it is somewhat difficult to determine exactly the magnitude of the intervention
using only data from poison control centers (e.g., Assargaard and Sjoberg5), the results are likely to underestimate the true effect
of child-resistant packaging.
Recommendations on legislation and child-resistant packaging
programs
Legislation requiring child-resistant packaging should be expanded to all drug
dispensed by pharmacies as well as over-the-counter medications, such as cough syrups,
aspirin, and cold tablets.
It is clear that child-resistant packaging reduces the incidence of poisonings.
Legislation should be established requiring child-resistant packaging where it is
not already in effect.
Recommendations for future research
A more rigorous approach to the randomized controlled study done by Dole and colleagues1
would be a good way to determine how compliant pharmacies are with the PPPA. Also,
an interrupted time series study done today might be able to determine if the decline
in poisonings has bottomed-out and, if so, may shed some light on possible ways
to decrease that incidence even further.
There is a need for the development of child-resistant packaging that will be resistant
to children yet easy for the elderly to use (i.e., cognitive rather than strength-based
designs).
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