The Trial Where Professional Pest Control Did Not Beat a Leaflet: Mouse Allergen, Asthma, and What Reduction Actually Bought

1. Introduction: the health claim, tested

Pest control in housing is justified on health grounds. Cockroaches and mice produce allergens, those allergens are associated with asthma morbidity, and removing the pests should therefore improve health.

Each step in that chain has been examined in randomised trials, and the results are more interesting than the claim.

1.1 What this paper argues

That the trials validate the target and not the delivery model, that a null result comparing two active interventions is frequently misreported, and that the dose-response finding underneath is the part a practitioner should act on.

This is not medical advice and nothing here concerns the management of any individual's asthma.

2. Why allergen is the mechanism

The premise, which is well supported.

Cockroach and mouse allergens have both been implicated as causes in inner-city asthma morbidity in multicenter studies.⁶ Exposure to mouse allergen is associated with increased asthma morbidity in children, and reduction in exposure is associated with improvements in asthma.³

2.1 The recommended approach

To minimise mouse allergen exposure, integrated pest management strategies are recommended, including removal of food sources for rodents, barring pathways of entry, and eliminating rodents already present through traps and rodenticides.⁷

That is a conventional description of rodent work, and it is the same combination this journal has argued for on purely entomological grounds in the rodent exclusion article.

2.2 The question the trials ask

Whether performing that work produces measurable health improvement, and whether having a professional perform it produces more improvement than telling a household how.

3. The trial

The Mouse Allergen and Asthma Intervention Trial.

It was a randomized clinical trial conducted in Baltimore, Maryland, and Boston, Massachusetts. Participants were mouse-sensitized and exposed children and adolescents aged 5 to 17 years with asthma, randomised to receive professionally delivered IPM plus pest management education, or pest management education alone. Enrollment occurred between May 2010 and August 2014, with final follow-up on 25 September 2015.¹

The trial enrolled 361 children with persistent asthma.²

3.1 The stated uncertainty

The authors framed the question precisely: professionally delivered IPM interventions can reduce home mouse allergen concentrations, but whether they reduce asthma morbidity among mouse-sensitized and exposed children and adolescents is unknown.¹

That is an unusually clean statement of what was and was not established beforehand. Allergen reduction was known to be achievable. Health benefit was not.

3.2 Why the population is the right one

Participants were both sensitised to mouse and exposed to it. That is the group in which an allergen intervention has the best chance of working, so a null result here is not explained by treating people for whom the allergen was irrelevant.

3.3 The enrichment principle

Selecting a population in which an effect is most likely is standard trial design, and it cuts both ways when reading the result.

A positive result in an enriched population may not generalise to a broader one. A null result in an enriched population is harder to explain away, because the conditions were as favourable as the investigators could make them.

3.4 The retention

Retention in the trial was reported at approximately 90 per cent.⁹

That matters because differential dropout is one of the ways a trial can generate a spurious null. Ninety per cent retention across a multi-year study in this population is good, and it removes one alternative explanation.

4. What the intervention consisted of

The professional arm received real pest control work.

Integrated pest management consisted of application of rodenticide, sealing of holes that could serve as entry points for mice, and trap placement.¹

4.1 This is the recommended practice

Rodenticide, exclusion and trapping is the standard combination, and the exclusion component is the one this journal has argued is the durable part.

So the intervention arm was not receiving a token service. It was receiving the approach the literature recommends, delivered professionally.

4.2 The ongoing element

Participants were repeatedly assessed for persistent or recurrent mouse infestation to determine if they would receive additional professional pest management.⁹

This was therefore not a single visit. The design allowed for repeat service where infestation persisted, which addresses the rebound problem this journal examined for cockroaches.

5. The comparator

The detail that determines how the result should be read.

The control arm received pest management education alone.¹

5.1 This is not a placebo

The comparison was not professional service against nothing. It was professional service plus education against education by itself.

Education about pest management is an active intervention. It tells a household what attracts mice, where they enter, and what to do, and households act on that.

5.2 Why this matters enormously

A trial comparing two active interventions that finds no difference has established that they perform similarly. It has not established that either is ineffective.

This is the single most common misreading of null results in clinical literature, and it applies directly here.

6. The eradication rate

Evidence that the professional arm did what it was supposed to do.

More than 60 per cent of participants in the IPM arm had complete eradication of their infestation.⁹

6.1 What that establishes

The intervention was delivered competently. This was not a failed service that produced a null result through non-delivery.

It also gives a useful benchmark. Complete eradication in over six of ten infested homes, with repeat service available, is a reasonable description of what professional rodent work achieves in occupied housing.

We are not aware of a comparable figure published anywhere in the trade literature. A randomised trial reporting its own eradication rate, in occupied homes, with follow-up, is a better source for what this work achieves than anything the industry publishes about itself, and it arrives as an incidental detail in a study about asthma.

6.2 The implied ceiling

It also means that in up to four of ten homes, complete eradication was not achieved despite professional service with follow-up. We would note that as a realistic expectation rather than a criticism.

7. The result

Stated plainly by the secondary analysis.

There were no differences in mouse allergen exposure or clinical outcomes between groups, but substantial reductions in mouse allergen occurred.²

7.1 The two halves

No difference between arms. Substantial reduction in both.

Education alone reduced mouse allergen about as much as education plus professional pest management did. That is a striking result for an industry whose health claim rests on doing the work rather than explaining it.

7.2 The explanations available

Several things could produce this pattern and the trial does not distinguish between them. The education may have been unusually good, since it was designed by investigators rather than handed over as a pamphlet. Households in a trial are observed, measured and visited, which is itself an intervention. And participation in a study about mice may motivate action in a way that ordinary advice does not.

Any of those would mean the control arm was stronger than routine education in the real world, which would make the comparison harder for the professional arm to win than it would otherwise be.

7.3 Why we are not using that to dismiss it

Those are reasons the null might overstate the case against professional delivery. They are hypotheses, not findings, and we flag them as ours.

The disciplined position is that the trial tested professional service against a well-delivered education programme and found no difference, and that generalising either way beyond that comparison requires evidence we do not have.

8. Why the null is not what it looks like

The question the trial answered was whether professional service adds to education, not whether pest management affects asthma.

8.1 Three readings, one correct

The wrong strong reading is that pest control does not help asthma. The trial does not support that, because both arms reduced allergen.

The wrong weak reading is that the trial shows nothing. It shows something specific and inconvenient: that the incremental value of professional delivery over education, in this population, was not detected.

The correct reading is that allergen reduction is what matters and that there is more than one way to achieve it, which §9 supports directly.

9. The dose response

The finding underneath the null, and the most important result in this paper.

In the trial, a dose response relationship was found between reduction in mouse allergen and improvement in asthma outcomes, regardless of the intervention implemented.³

9.1 Why this rescues the premise

The chain from allergen to asthma holds. Where allergen fell, outcomes improved, and the relationship was graded rather than all-or-nothing.

What the trial failed to show is that a particular delivery mechanism was necessary to produce the fall. Those are separate propositions and the trial separates them cleanly.

9.2 The analytical status

A dose-response relationship observed within a trial is not the randomised comparison. Households achieving large reductions may differ systematically from those that did not, and §19 shows the investigators looked for such differences.

We flag that this finding is observational within a randomised trial, which is stronger than an ordinary observational study and weaker than the primary comparison.

10. The seventy-five per cent threshold

The magnitude that mattered.

The trial demonstrated that a reduction in mouse allergen exposure of at least 75 per cent from baseline, among mouse-sensitised and exposed asthmatic children randomised to either arm, was associated with greater increases in FEV1 and forced expiratory flow between 25 and 75 per cent of forced vital capacity over one year.⁴

10.1 Why a threshold this high matters

Three quarters is a large reduction. It implies that modest improvement in a home is unlikely to register as clinical benefit, and that the target is substantial rather than incremental change.

Achieving a clinically meaningful reduction in mouse allergen levels is described as challenging.³

10.2 The implication for service design

If the benefit appears at large reductions, then partial suppression is not a partial health benefit. That is an argument for thoroughness over frequency, and we would flag it as our inference from the threshold.

11. What improved

The outcomes that moved were lung function measures: FEV1 and forced expiratory flow between 25 and 75 per cent of forced vital capacity, over one year.⁴

11.1 Why these are meaningful

These are spirometric measures rather than symptom reports, so they are not subject to reporting bias in an unblinded trial. In a study where participants know which arm they are in, an objective measure carries more weight than a questionnaire.

The flow measure in particular is often interpreted as reflecting smaller airways, which is where persistent asthma pathology sits.

11.2 What did not move

It is worth being precise about the contrast with §12, where the outcome examined was medication step and there were no differences in other measured asthma outcomes.⁶

Lung function responding while medication step and symptom measures do not is a coherent pattern rather than a contradiction. A physiological improvement can be real and still be too small to change a prescribing decision, particularly over one year and particularly in patients whose therapy is already optimised.

11.3 The honest reading of that

An effect that appears on spirometry and not on medication or symptoms is a modest effect. We would rather describe it that way than present the dose-response finding as though it demonstrated large clinical gains, because it does not.

What it demonstrates is that the mechanism is real and that its size, at the reductions achieved in these trials, is at the edge of what these outcome measures detect.

12. The second null result

A separate trial, with a different design and a compatible conclusion.

In that study, subjects in the intervention group significantly reduced all measured allergen levels, being cat, dog and dust mite allergens in the bedroom and cockroach and mouse allergens in the kitchen and bedroom, while those in the control group reduced only dust mite and mouse allergens in the bedroom and cockroach allergen in the kitchen.⁶

12.1 The outcome measure

Participants in the intervention arm reduced therapy from step 4.4 at randomization to 3.50 after intervention, while the control arm reduced from 4.4 to 3.4.⁶

There were no differences in other measured asthma outcomes.⁶

12.2 The pattern repeating

Here the intervention arm achieved broader allergen reduction than the control, and the clinical outcome still did not separate. Both arms reduced medication by about the same amount.

13. The controller therapy condition

The qualification the authors attached, which is essential to reading the result.

The conclusion was that targeted allergen avoidance measures do not allow for reduction in asthma pharmacologic therapy compared with usual care in patients already receiving optimal controller therapy.⁶

13.1 The scope of that claim

The qualifier is doing substantial work. The population was already receiving optimal controller therapy, which is to say their asthma was already being managed pharmacologically to a good standard.

A ceiling effect is the obvious explanation. Where medication has already brought outcomes close to the achievable range, an environmental intervention has little room to demonstrate additional benefit.

13.2 What this does not address

The trial does not speak to populations without access to optimal controller therapy, or to those whose asthma is poorly controlled despite it. Those are the groups in whom environmental intervention would be most plausible, and they are not the group studied.

We flag the ceiling effect interpretation as ours rather than the authors'.

14. What a smaller trial showed about allergen

The allergen endpoint on its own, where the effect is unambiguous.

Eighteen homes of children with positive mouse allergen skin test results and at least mild persistent asthma in urban Boston, with evidence of mouse infestation or exposure, were randomised in a 2 to 1 ratio, twelve intervention and six control homes. The intervention consisted of filling holes with copper mesh, vacuuming and cleaning, and using low-toxicity pesticides and traps, with dust sampled for mouse allergen and cockroach allergen at baseline and at one, three and five months.⁵

14.1 Why the method is familiar

Copper mesh in holes is exactly the exclusion material this journal examined at length in the rodent exclusion article, chosen there on the basis of incisor mechanics. It appears here as a clinical trial intervention.

15. The control group that got worse

The comparison that makes the allergen result vivid.

Mouse allergen levels were significantly decreased compared with control homes by the end of the intervention period at month five in the kitchen and bedroom, with the kitchen intervention showing a 78.8 per cent reduction while the control showed a 319 per cent increase, at P equal to 0.02.⁵

15.1 The untreated trajectory

The control homes did not stay level. Allergen rose substantially over five months.

That is worth holding alongside §7. Where a control group receives no education and no service, the allergen burden increases; where it receives education, allergen falls about as much as with professional service. The active ingredient looks like the household knowing what to do.

15.2 The size caveat

Twelve intervention homes and six controls is a very small trial, and a percentage change in a control group of six homes is unstable.⁵ We report the direction with more confidence than the magnitude.

16. Separating target from delivery

Pulling the threads together.

The target is validated. Allergen exposure is associated with morbidity, reduction is associated with improvement, and the relationship within the trial was graded.³⁴

The delivery model is not. Professional IPM plus education did not outperform education alone on exposure or clinical outcomes.¹²

16.1 Why both can be true

If what matters is that allergen falls by a large amount, and a household given good information can achieve that, then the professional adds convenience, speed and reliability rather than a different outcome.

That is a real but smaller claim than the one usually made, and we think it is the honest one.

16.2 The wider trial literature

These are not the only attempts. The surrounding literature includes work on the effectiveness of an integrated pest management intervention in controlling cockroaches, mice and allergens in New York City public housing; the Seattle-King County Healthy Homes Project, a randomized controlled trial of a community health worker intervention to decrease exposure to indoor asthma triggers; and the National Cooperative Inner-City Asthma Study environmental intervention to reduce cockroach allergen exposure in inner-city homes.⁸

16.3 The pattern across them

Two features recur. The interventions are multi-component, combining pest management with education and often with a community health worker, and the comparison is rarely against nothing.

That makes the body of evidence good at establishing that allergen can be reduced and poor at isolating which component did it. We would identify that as the central methodological problem in this field rather than a flaw in any one study.

16.4 The one-time question

A further trial set out to evaluate the effects of a one-time, apartment-level integrated pest management intervention on healthcare utilization and asthma symptoms among children with persistent asthma.⁸

That design tests something different and practically important: whether a single professional visit is enough. Given the rebound dynamics this journal has examined in rodents and cockroaches, we would expect a one-time intervention to face the same problem, and the repeat-service provision in §4.2 suggests the trialists thought so too.

17. The school finding

An observation from the same research programme that reframes the whole exercise.

Regression models of log-transformed variables showed significantly higher settled dust levels of mouse, cat and dog allergens in schools than homes, specifically 545 per cent higher for Mus m 1, the mouse allergen, with an estimated absolute difference of 0.55 micrograms per gram; 198 per cent higher for cat allergen; and 144 per cent higher for dog allergen.⁶

Airborne and settled dust mouse allergen levels in classrooms were moderately correlated, and there were undetectable to very low levels of cockroach and dust mite allergens in both homes and schools.⁶

18. Why the school finding matters

It relocates the exposure.

If mouse allergen in classrooms is several times the level in the children's homes, then a child attending school spends a substantial part of each weekday in the higher-exposure environment.

18.1 The consequence for home intervention

An intervention that eliminates mouse allergen in a home is addressing a fraction of total exposure. That is a plausible contributing explanation for why home interventions have struggled to demonstrate clinical benefit, and it is one the trials could not control for.

We flag this as our inference. The school measurement and the home trials come from related programmes but the connection we are drawing is ours.

18.2 The cockroach contrast

Cockroach allergen was undetectable to very low in both settings in that sample.⁶ Allergen burden is not uniform across pest species or across places, and a programme aimed at the wrong one in the wrong building achieves nothing regardless of how well it is executed.

18.3 The measurement point

Airborne and settled dust mouse allergen in classrooms were moderately correlated at an r of 0.48.⁶

Moderate rather than strong correlation means settled dust is an imperfect proxy for what is actually breathed. Most of the trial evidence in this paper uses settled dust because it is practical to collect, and the outcome that matters is airborne exposure.

We would note that as a general caution on this literature rather than a criticism of any study. It is the same distinction between a convenient measurement and the quantity of interest that this journal raised about trap counts and about mass loss in decayed timber.

19. What cannot be predicted

A negative finding from the secondary analyses worth recording.

Investigators from the same trial, in secondary analyses, were unable to pinpoint a specific clinical characteristic studied, such as level of atopy, lung function, or mouse IgE level, that predicted improvement in asthma following mouse allergen reduction.⁴

A further secondary analysis examined whether other indoor exposures modified the effect, hypothesising that lower baseline mouse allergen, lower particulate matter, and absence of sensitisation and exposure to other indoor allergens would be associated with greater response.²

19.1 What that means practically

There is no available test that identifies in advance which household will benefit. Targeting the intervention to likely responders is not currently possible on the characteristics examined.

19.2 The housing angle

A separate analysis aimed to identify baseline housing characteristics associated with successful mouse allergen reduction so that environmental interventions could be tailored to optimise chances of success.³

That is the right question, and it moves the targeting problem from the patient to the building, which is where a pest control company would have something to contribute.

19.3 What a building-level predictor would need to be

Something observable on a first visit that predicts whether a seventy-five per cent reduction is achievable. Construction type, the number and accessibility of entry points, whether adjacent units are infested, and whether the occupant can act on advice are the candidates an operator would nominate.

We are speculating. The analysis exists and we have not read its results,³ and we raise it because it is the point at which this literature and this trade could usefully meet.

20. What this means for a pest control company

The uncomfortable part, stated directly.

The strongest available trial of professionally delivered pest management as a health intervention did not show it outperforming teaching people to do it themselves.¹²

20.1 What we should stop claiming

That professional service produces health outcomes a well-informed household could not achieve. That claim is not supported by the trial evidence we have found.

20.2 What the education arm implies

If education alone produced substantial allergen reduction, then the information is the active component, and a company that withholds it in order to sell repeat visits is withholding the part that worked.

We would go further, as our position: explaining the exclusion points, the food and water sources and the reasoning to a client is not a courtesy added to the service. On this evidence it may be the most effective thing performed during the visit.

21. What we would still claim

The case that survives.

Large reductions are what matter. Benefit appeared at reductions of at least 75 per cent.⁴

Eradication is achievable but not universal. Over 60 per cent of professionally treated homes reached complete eradication.⁹

Untreated homes do not stay level. Control kitchens rose over five months.⁵

Exclusion is a clinical trial intervention. Filling holes with copper mesh and sealing entry points appear in the protocols.¹⁵

Persistence requires follow-up. Repeat assessment for recurrent infestation was built into the design.⁹

21.1 The honest summary

A professional can reliably and quickly achieve the large reduction that the evidence associates with benefit, in a population where doing it yourself is harder than a leaflet implies. That is a defensible claim. It is not the same as claiming the service is necessary for the outcome.

21.2 The evidence that cuts the other way

We should record a finding that supports the service, because it exists and because this article has been hard on the industry.

Trial documentation notes that, while not a randomised controlled trial, evidence from a community asthma initiative indicated that home based education and integrated pest management referrals improved health outcomes and were highly cost-effective in reducing hospital and health care utilization costs, suggesting that interventions to reduce exposures are important in reducing asthma morbidity.¹⁰

21.3 How to weigh that against the trials

It is programme evaluation rather than randomised evidence, and the authors say so themselves.¹⁰ It cannot separate the effect of the referral from everything else a community asthma initiative does.

But it measures a different outcome. The randomised trials measured symptoms, lung function and medication step; this measures hospital and healthcare utilisation and cost. An intervention can fail to move a spirometry reading and still reduce admissions, and those are not the same question.

21.4 Where that leaves us

The strongest evidence on clinical outcomes is null on delivery. The weaker evidence on utilisation and cost is favourable. We think the honest position is that the case for professional service rests more on reliability, speed and reach into households that will not act on a leaflet than on a demonstrated clinical advantage, and that this is a defensible basis for a public programme even where it is a weak basis for a marketing claim.

22. Limitations and open questions

This is not medical advice. Nothing here concerns the management of any individual's asthma, and environmental measures are not a substitute for clinical care.

We have read abstracts and secondary analyses rather than full primary reports. The trial results reach us through PubMed records, secondary analysis papers and review material.¹²³⁴

The dose-response finding is observational within a randomised trial. Stated in §9.2.

One trial is very small. Twelve intervention and six control homes, as noted in §15.2.⁵

The second null trial's population was already optimally medicated. Stated in §13, and the ceiling effect reading is ours.⁶

All of this evidence is from United States inner-city settings. Baltimore, Boston and comparable populations. Transfer to Canadian housing stock, to Manitoba, or to detached suburban housing is an assumption we have not tested, and mouse pressure, construction type and climate all differ.

Sections 8, 10.2, 13.1, 18.1 and 20.2 are our reasoning. The reading of the null result, the thoroughness inference, the ceiling effect interpretation, the school exposure argument and the conclusion about education are ours rather than sourced positions.

Our commercial position. This company sells rodent and cockroach control and benefits from the belief that professional service produces health outcomes. The best available trial does not show that it outperforms education. We think publishing that is better than not, and §21 sets out what we would still defend.

23. Conclusion

The Mouse Allergen and Asthma Intervention Trial randomised 361 mouse-sensitised and exposed children with asthma to professionally delivered integrated pest management plus education, or to education alone.¹² Over sixty per cent of the treated arm achieved complete eradication.⁹ There were no differences between the arms in allergen exposure or clinical outcome, because substantial reductions occurred in both.²

Underneath that, a dose-response relationship was found between allergen reduction and asthma improvement regardless of which intervention produced it, with reductions of at least seventy-five per cent from baseline associated with greater gains in lung function over a year.³⁴ The target is real. The claim that a professional is required to hit it is the part that did not survive.

There is a version of this finding that is bad news for this trade and a version that is not. The bad version is that the service is unnecessary. The better-supported version is that the information is the active ingredient, that a household which understands where mice enter and what sustains them can achieve most of what a technician achieves, and that the professional's real contribution is doing it reliably, quickly and completely in the homes where that is hard. That is a smaller claim than the industry usually makes and it has the advantage of being what the evidence shows.

References

1. Effect of an Integrated Pest Management Intervention on Asthma Symptoms Among Mouse-Sensitized Children and Adolescents With Asthma: A Randomized Clinical Trial. PubMed record 28264080. Primary trial record. Used for the statement that professionally delivered integrated pest management interventions can reduce home mouse allergen concentrations but whether they reduce asthma morbidity among mouse-sensitized and exposed children and adolescents is unknown; for the design as a randomized clinical trial conducted in Baltimore, Maryland and Boston, Massachusetts with mouse-sensitized and exposed children and adolescents aged 5 to 17 years with asthma randomised to receive professionally delivered integrated pest management plus pest management education or pest management education alone; for the enrollment period of May 2010 to August 2014 with final follow-up on 25 September 2015; and for the description of the intervention as consisting of application of rodenticide, sealing of holes that could serve as entry points for mice, and trap placement. https://pubmed.ncbi.nlm.nih.gov/28264080/
2. Indoor Environmental Factors May Modify the Response to Mouse Allergen Reduction Among Mouse-Sensitized and Exposed Children with Persistent Asthma. PubMed Central PMC8671238. Secondary analysis of the same trial. Used for the description of the Mouse Allergen and Asthma Intervention Trial as a randomized clinical trial of children aged 5 to 17 years with persistent asthma testing the effect of an intensive pest management programme focused on mouse allergen versus pest management education alone; for the statement that there were no differences in mouse allergen exposure or clinical outcomes between groups but substantial reductions in mouse allergen occurred; for the trial size of 361 children across Baltimore and Boston; and for the secondary analysis hypothesis that lower baseline mouse allergen, lower particulate matter of 10 micrometres or less, and absence of sensitisation and exposure to other indoor allergens would be associated with greater response to mouse allergen reduction. https://pmc.ncbi.nlm.nih.gov/articles/PMC8671238/
3. Predictors of Successful Mouse Allergen Reduction in Inner-City Homes of Children with Asthma. PubMed Central PMC8578252. Used for the statements that exposure to mouse allergen is associated with increased asthma morbidity in children and that reduction in exposure is associated with improvements in asthma; for the finding that in the Mouse Allergen and Asthma Intervention Trial a dose response relationship was found between reduction in mouse allergen and improvement in asthma outcomes regardless of the intervention implemented; for the statement that achieving a clinically meaningful reduction in mouse allergen levels can be challenging; and for the aim of identifying baseline housing characteristics associated with successful mouse allergen reduction so that environmental interventions could be tailored to optimise chances for success. https://pmc.ncbi.nlm.nih.gov/articles/PMC8578252/
4. Do Baseline Asthma and Allergic Sensitization Characteristics Predict Responsiveness to Mouse Allergen Reduction? Journal of Allergy and Clinical Immunology: In Practice. Used for the finding that the Mouse Allergen and Asthma Intervention Trial demonstrated that a reduction in mouse allergen exposure of at least 75 per cent from baseline, among mouse-sensitised and mouse-exposed asthmatic children randomised to integrated pest management plus education or education alone, was associated with greater increases in FEV1 and forced expiratory flow between 25 and 75 per cent of forced vital capacity over one year; and for the report that investigators from the same trial were unable in secondary analyses to pinpoint a specific clinical characteristic studied, such as level of atopy, lung function or mouse IgE level, that predicted improvement in asthma following mouse allergen reduction. https://www.sciencedirect.com/science/article/abs/pii/S221321981930769X
5. Effect of environmental intervention on mouse allergen levels in homes of inner-city Boston children with asthma. Annals of Allergy, Asthma and Immunology. Used for the design in which eighteen homes of children with positive mouse allergen skin test results and at least mild persistent asthma in urban Boston with evidence of mouse infestation or exposure were randomised in a 2 to 1 ratio, twelve intervention and six control homes; for the intervention consisting of filling holes with copper mesh, vacuuming and cleaning, and using low-toxicity pesticides and traps, with dust sampled for major mouse allergen and cockroach allergen at baseline and at one, three and five months; and for the result that mouse allergen levels were significantly decreased compared with control homes by the end of the intervention period at month five in the kitchen and bedroom, with the kitchen intervention showing a 78.8 per cent reduction against a 319 per cent increase in the control at P equal to 0.02. https://www.sciencedirect.com/science/article/abs/pii/S1081120610617772
6. Record for Effect of an Integrated Pest Management Intervention on Asthma Symptoms Among Mouse-Sensitized Children and Adolescents With Asthma, together with associated abstracts from the same research programme. Used for the statement that cockroach and mouse allergens have both been implicated as causes in inner-city asthma morbidity in multicenter studies; for the allergen avoidance trial results in which the intervention group significantly reduced all measured allergen levels including cat, dog and dust mite in the bedroom and cockroach and mouse in kitchen and bedroom while the control group reduced only dust mite and mouse in the bedroom and cockroach in the kitchen, with the intervention arm reducing National Asthma Education Prevention Program based therapy from step 4.4 at randomization to 3.50 and the control arm from 4.4 to 3.4 at P equal to 0.76, no differences in other measured asthma outcomes, and the conclusion that targeted allergen avoidance measures do not allow for reduction in asthma pharmacologic therapy compared with usual care in patients already receiving optimal controller therapy; and for the school and home comparison showing significantly higher settled dust levels of mouse, cat and dog allergens in schools than homes, 545 per cent higher for Mus m 1 with an estimated absolute difference of 0.55 micrograms per gram, 198 per cent higher for cat allergen and 144 per cent higher for dog allergen, with airborne and settled dust mouse allergen in classrooms moderately correlated and undetectable to very low levels of cockroach and dust mite allergens in both homes and schools. https://www.researchgate.net/publication/314271008_Effect_of_an_Integrated_Pest_Management_Intervention_on_Asthma_Symptoms_Among_Mouse-Sensitized_Children_and_Adolescents_With_Asthma_A_Randomized_Clinical_Trial
7. Update on indoor allergens and their impact on pediatric asthma. Annals of Allergy, Asthma and Immunology. Review source. Used for the statement that to minimise mouse allergen exposure, integrated pest management strategies should be used including removal of food sources for rodents, barring pathways of entry, and eliminating rodents already present through traps and rodenticides; and for its description of the Mouse Allergen and Asthma Intervention Trial as randomising mouse-sensitised children with asthma to pest management education with formal home integrated pest management or pest management education alone. https://www.annallergy.org/article/S1081-1206(22)00119-3/fulltext
8. A randomized trial of a one-time pest intervention: impact on childhood asthma outcomes. Journal of Asthma. doi:10.1080/02770903.2019.1709870. Cited for its stated objective of evaluating the effects of a one-time, apartment-level integrated pest management intervention on healthcare utilization and asthma symptoms among children with persistent asthma, and for identifying the surrounding literature relied on here, including the effectiveness of an integrated pest management intervention in controlling cockroaches, mice and allergens in New York City public housing, the Seattle-King County Healthy Homes Project randomised controlled trial, and the National Cooperative Inner-City Asthma Study environmental intervention to reduce cockroach allergen exposure in inner-city homes. https://www.tandfonline.com/doi/full/10.1080/02770903.2019.1709870
9. Mouse Allergen and Asthma Intervention Trial, protocol and statistical analysis plan, ClinicalTrials.gov record NCT02251379. Trial documentation. Used for the description of the trial as a multi-centre randomised controlled trial of a mouse allergen exposure intervention with participants randomised to either the integrated pest management or the education arm at approximately 90 per cent retention; and for the statement that participants were repeatedly assessed for persistent or recurrent mouse infestation to determine if they would receive additional professional pest management, with more than 60 per cent of participants in the integrated pest management arm having had complete eradication of their infestation. https://cdn.clinicaltrials.gov/large-docs/79/NCT02251379/Prot_SAP_000.pdf
10. School Inner-City Asthma Intervention Study, protocol documentation, ClinicalTrials.gov record NCT02291302. Trial documentation. Used for the description of an intervention trial in Boston and Baltimore using an established targeted method to decrease mouse allergen in homes of children with asthma, and for the observation that while not a randomised controlled trial, evidence from a community asthma initiative indicated that home based education and integrated pest management referrals improved health outcomes and were highly cost-effective in reducing hospital and health care utilization costs. https://cdn.clinicaltrials.gov/large-docs/02/NCT02291302/Prot_SAP_000.pdf