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).