To be eligible to participate in the focus groups, participants had to (1) fit into either the younger or the older age group and (2) own a single-family home equipped with a natural gas or oil-burning furnace. A professional marketing research company recruited participants from an existing research database and through media advertisements. The recruiter contacted potential participants by telephone, assessed their interest and screened them for eligibility. Individuals with careers in the HVAC, health or media fields were not eligible to participate.

In August 2009, the 2-hour focus groups were conducted at a market research facility in Chicago. Upon arrival, participants were administered a written informed consent and asked to complete a demographic and product usage questionnaire. A trained moderator conducted each group using a semistructured guide that explored the topics of furnace safety and maintenance, knowledge of CO and CO poisoning, CO alarm usage, and preferred sources of safety information. All of the focus group discussions were recorded and transcribed, and participants received a $75 incentive at the end of the session. The study design was reviewed and approved to ensure protection of the subjects by Institutional Review Boards at RTI and CDC, the contractor and sponsor, respectively, for the study.

Following each focus group, the study team debriefed to identify salient findings and note possible patterns and themes expressed in the groups. After completing data collection, the data were entered into an ordered meta-matrix that segmented responses by group and question. This approach organised the large volume of data for cross-case analysis, a common technique used in qualitative research.^18–20 Three researchers independently reviewed the meta-matrix to identify patterns and themes within each topic, and the lead author refereed the few discrepancies in interpretation.

The quantitative data from the demographic and product questionnaire were also entered into a spreadsheet, which was used to describe participants’ characteristics (eg, education) and behaviours (eg, home safety purchases, smoke alarm installation). Given the study design, no statistical tests were conducted on the quantitative responses.

A total of 29 individuals participated in the focus groups (table 2). Participants were generally diverse in education, income and sex. However, most of the individuals who participated in the younger (aged 25–45) focus groups had earned a college degree or a postgraduate degree.

Most participants thought regular maintenance was an important precaution in furnace safety; however, participants’ definition of maintenance varied, and few scheduled or performed furnace inspections consistently. In the previous year, most participants from both age groups had personally inspected their furnace, and a few had arranged professional inspections. However, many participants admitted going years between inspections, suggesting that maintenance is sporadic, rather than regular, for many homeowners.

Participants who arranged professional inspections were likely to have furnace or appliance service contracts. In these cases, participants scheduled twice-yearly HVAC inspections, and a professional prepared the furnace for winter by checking its emissions and functionality. Conversely, participants who inspected the furnace themselves primarily changed filters, checked the flame colour, vacuumed the burner tray, cleaned out dust and debris, and conducted soap tests to check for natural gas leaks. While useful and important, these tasks are unlikely to detect malfunctions that could lead to CO poisoning.

Despite their behaviour, participants generally supported the idea of regular furnace inspections, and they primarily cited economic benefits, such as improving furnace efficiency, preventing costly repairs and ensuring safety. Many participants also emphasised the cost savings of a properly working furnace, and several compared an annual furnace inspection to regularly changing the oil in one’s car. Younger participants, in particular, emphasised efficiency and avoidance of costly repairs, whereas older participants emphasised safety.

Participants cited several reasons for not regularly inspecting or maintaining furnaces. First, they suspected that a professional inspection would be expensive, and they feared it might uncover the need for costly repairs. Second, they were unsure what services need to be performed during inspection and uncertain which tasks require a professional to do them. Concern about finding a reputable professional also was a major barrier. Many participants were unsure how to identify a qualified, trustworthy professional and how to distinguish between warranted and unwarranted repairs.

When asked how to encourage furnace inspections, some participants suggested free or subsidised inspections by natural gas and utility companies. Others suggested providing reminders in gas and utility bills, administering reminder calls from the gas company and educating consumers on what to expect during a professional furnace inspection. A few participants also recommended providing tips to help consumers select a reputable HVAC or inspection professional.

Participants accurately described CO as an odourless and colourless gas. Nevertheless, many were confused about the difference between natural gas and CO. Some participants regularly interchanged these terms and, in one group, a few were unsure whether they could smell CO if it is in their homes.

Several participants also identified CO as a ‘silent killer,’ knew that it often affected sleeping individuals and recalled that victims were unlikely to know they were being poisoned. Participants correctly identified many of the symptoms of CO exposure (eg, headache, drowsiness and dizziness) and could correctly name multiple sources of CO (eg, grills, furnaces, gas fireplaces, kerosene space heaters, gas clothes dryers, gas stoves and automobiles).

When asked how they would respond if they found CO in the home, most participants said they would leave the house and call the fire department or gas company. However, a handful of participants suggested less appropriate actions, including calling a repair professional, turning off the natural gas supply, opening windows to ventilate the home and investigating the CO alarm for a malfunction, all without leaving the home or seeking fresh air.

Participants admitted that while they thought CO poisoning was an important safety issue, they did not think about it regularly. When asked why, they suggested that the absence of a traditional visual warning symbol—in contrast to graphic warnings for home fires and gas explosions—made remembering CO poisoning difficult. Participants also reported that CO poisoning was often excluded from safety awareness activities, whereas fire safety is commonly covered.

Almost all participants were aware of CO alarms, and most reported having at least one in their home. (Note: Most Chicago municipalities have housing codes that require CO alarms.) Half of the participants had multiple alarms in their homes and placed them on multiple stories; however, the other half of participants had only a single alarm in their homes. Many, but not all, of the participants were aware that CO alarms are a housing code requirement in Chicago, which may explain why more participants in this study reported ownership of CO alarms than has been found in previous studies.¹²¹³

Because CO alarms could have been purchased by previous homeowners, the ability of participants to replace and maintain their CO alarms was also assessed. Participants knew they could purchase CO alarms at home improvement stores as well as at general and online retailers. Nevertheless, participants inconsistently maintained their CO alarms. While some changed the alarm batteries every 6 months (as recommended), many simply waited until the alarm beeped, signalling low power. This finding is consistent with earlier research.¹³

Many participants were unsure where CO alarms should be placed in the home and how many should be installed. Most participants placed CO alarms near furnaces or gas appliances, many of which were in basements or utility rooms. Others placed the alarms in more appropriate locations, such as in bedrooms, hallways or dining rooms. Several participants stated that CO alarms should be located near smoke alarms. None of the participants acknowledged a connection between the location of a CO alarm and one’s ability to hear it.

Very few participants had seen or heard educational information on CO poisoning. Some recalled seeing news features (eg, 60 Minutes) or articles in parenting magazines. Local news stories about CO poisoning deaths and injuries, while not educational, were the most common source of CO information. When asked about trusted sources of health and safety information, younger participants rated television and internet news sites as preferred sources, whereas older participants preferred newspapers and television newscasts.

Participants offered several recommendations for educating homeowners about CO poisoning, such as having realtors educate new homeowners, especially during home inspections, or providing CO safety information in schools, which children would likely share with parents. Many participants recommended public service announcements or reminder notices on natural gas and utility bills. Several participants also proposed featuring CO safety at health fairs or shopping mall kiosks.

Additionally, participants recommended several strategies for encouraging CO alarm installation and regular furnace maintenance. For example, coupons, discounts and homeowner insurance rebates were mentioned as valuable incentives for professional furnace inspections. Several participants suggested tax breaks for replacing older furnaces, and some favoured updating housing codes to require CO alarms. Finally, many participants recommended coupons or group/neighbourhood discounts on alarm purchases.

These findings have several implications for preventing residential CO poisoning (table 3). First, they suggest that heightening homeowners’ awareness of CO poisoning and educating homeowners on the proper placement and maintenance of CO alarms may be especially effective. These protective behaviours are relatively easy to adopt and require little investment from homeowners. For instance, most study participants had heard of CO and, despite some misconceptions, knew that it subtly poisons victims. Consequently, creating a visual warning symbol and incorporating CO safety into fire safety programmes might heighten homeowner awareness.

Similarly, many participants already own CO alarms. However, half of these participants installed the alarms in inappropriate locations, such as near major appliances (increasing the risk of nuisance alarms) or far from bedrooms (decreasing the likelihood of hearing the alarm sound). Therefore, providing diagrams for proper alarm installation and partnering with manufacturers to include the diagrams in CO alarm packaging might increase appropriate alarm placement.

Helping and incentivising homeowners to schedule annual furnace inspections may be more challenging. Given that many participants believed that personal (rather than professional) inspections are sufficient and that they cited several barriers to professional inspections, they may be less likely to adopt this protective behaviour. Nevertheless, participants suggested that financial incentives and reminders from trustworthy sources might convince them to schedule annual inspections. Consequently, inserting reminders in gas or utility bills, providing tips on finding a trustworthy inspector, and publishing regional inspection cost estimates might make inspections more accessible and less intimidating to homeowners.

Study participants’ input suggests that the timing of reminders and incentives can also maximise homeowner receptivity to furnace inspections. For instance, realtors and home inspectors could educate homeowners about furnace maintenance during the home purchase, particularly for first-time buyers. Also, inserting reminders into utility bills or electronic billing notices in mid-autumn might encourage homeowners to schedule an inspection as temperatures dip and they begin using the furnace.

Finally, participants saw several organisations and individuals as trustworthy informational sources, and health professionals might partner with these groups to promote CO safety. Specifically, participants believed that natural gas companies, utility companies, schools, fire-fighters, realtors and home insurance agents are credible sources for home safety information. Partnering with these groups—as well as other home service professionals, such as home health aides and weatherisation contractors—to provide education (such as health fairs) and incentives (such as insurance discounts for CO alarm installation) might be an effective approach.

Because of limitations in sample size and geography, this study is exploratory and has four main limitations. First, all the beliefs and attitudes surrounding residential CO poisoning may not have been identified, and using a larger sample may have uncovered additional results. Second, the focus groups were conducted in Chicago, an area where housing codes require CO alarm installation; therefore, knowledge of CO and rates of CO alarm ownership are likely lower in areas where alarms are not required.¹³ Third, the study focused on a single CO poisoning scenario, residential exposure, and did not explore CO poisoning caused by motor vehicles, generator use during power outages, recreational activities (eg, boats, private airplanes) or industrial equipment. These other CO poisoning scenarios are likely associated with different risk and protective behaviours. Finally, this is a qualitative study conducted with a self-selected sample in group discussion settings. Hence, the findings are of limited generalisability, and participants’ responses may have been influenced by the focus group discussions and dynamics.

This study identified and examined some of the underlying knowledge, attitudes and beliefs that lead homeowners to adopt risk and protective behaviours for residential CO poisoning. The results show that CO risk behaviours are not random or thoughtless, but rather that homeowners may avoid professional furnace inspections because of fears of costly repairs and unscrupulous contractors and that they select CO alarm locations based on misconceptions. Understanding why homeowners adopt risk and protective behaviours can enable health professionals to educate them more effectively about CO poisoning, to disseminate information through trustworthy organisations and individuals, and to provide incentives for adopting protective behaviours.