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Keywords:

  • Heart failure

Abstract

  1. Top of page
  2. Abstract
  3. Materials and Methods
  4. Results
  5. Discussion
  6. Footnotes
  7. Acknowledgment
  8. References

Background: Owners' perceptions and priorities regarding quality of life (QoL) are important considerations given the unknown efficacy of many commonly administered medications, stress of hospital visits, difficulties providing home care, and personal choices including euthanasia.

Objective: To describe the relative importance of quality versus quantity of life to owners of cats with heart disease.

Animals: Two hundred and thirty-nine cats with heart disease.

Methods: Prospective questionnaire-based clinical study. Cat owners completed a questionnaire to identify important parameters when assessing their cat's QoL, the relative importance of quality versus quantity of life, and willingness to trade survival time for QoL. Variables associated with these parameters were evaluated with multivariate analyses.

Results: Appetite, owner interaction, sleep patterns, and litterbox habits were deemed important to QoL. Concern over pet suffering was significantly greater than concern over life expectancy. Ninety-three percent of owners were willing to trade survival time for good QoL; 57% of these were willing to trade up to 6 months. On multivariate analysis, the only factor significantly (P= .002) associated with willingness to trade 6 months was study site. Owner concern regarding stress of administering medications at home increased with number and frequency of medications.

Conclusions and Clinical Relevance: These results indicated that QoL is more important to owners of cats with heart disease than longevity. The various priorities and concerns of cat owners should be taken into account in order to provide optimal care.

Abbreviations:
ACE

angiotensin converting enzyme

ISACHC

International Small Animal Cardiac Health Council

QoL

quality of life

A shared goal of both veterinarians and owners of cats with heart disease is the provision of high quality of life (QoL) while simultaneously extending quantity of life. With rare exceptions, curative treatment of heart disease in cats is not achievable, and therapy is directed toward palliation of clinical signs and maximizing survival time in a progressive disease. Treatment of cardiomyopathy in cats can be particularly challenging because of the lack of evidence-based therapy. Thus, treatment of affected cats typically consists of medications that improve QoL, such as diuretics to relieve congestion, as well as agents such as angiotensin converting enzyme (ACE) inhibitors, beta-blockers, calcium-channel blockers, and antithrombotics that are thought to increase longevity. In veterinary medicine, quality and quantity of life are intertwined in that euthanasia is commonly elected when treatment fails to maintain adequate patient QoL. Moreover, if a prescribed medication incurs a negative effect such as adverse effects, increased need for monitoring or hospital visits, or difficulty in administering medication, treatment in itself could decrease perceived quality or quantity of life. In formulating and monitoring treatment regimens, veterinarians are likely guided by the owner's perception of their cat's QoL; however, the specific priorities, perceptions, and parameters that cat owners use to assess their cat's QoL have not been well described. Knowledge of specific parameters could improve communication regarding treatment regimes as well as decision-making regarding euthanasia. In a previous study of dogs with heart disease, we found that owners generally value quality over quantity of life, and the majority of owners would be willing to trade some amount of survival time for good QoL.1 By better understanding owner priorities regarding their pet's quality versus quantity of life, the clinician and cat owner can better align themselves toward individualized and more effective therapy for the animal. In this study, we sought to identify parameters that owners consider important when assessing their cat's QoL, to determine the relative importance of quality versus quantity of life, and finally, identify what variables, if any, influenced these perceptions and priorities.

Materials and Methods

  1. Top of page
  2. Abstract
  3. Materials and Methods
  4. Results
  5. Discussion
  6. Footnotes
  7. Acknowledgment
  8. References

The study was designed as a prospective multicenter trial involving pet owners whose cats were diagnosed with heart disease using a previously described questionnaire-based methodology.1 During their visit to the cardiology services of the University of Pennsylvania (Philadelphia, PA), Tufts University (North Grafton, MA), The Animal Medical Center (New York, NY), Veterinary Specialists of Rochester (Rochester, NY), Veterinary Emergency Clinic (Toronto, Canada), Animal Care Center (Rohnert Park, CA), Angell Animal Medical Center (Boston, MA), Ontario Veterinary College (Guelph, Canada), Hudson Valley Veterinary Cardiology (Sloatsburg, NY), or The Ohio State University (Columbus, OH), an owner of each cat was asked to complete a questionnaire regarding their cat's overall QoL as well as the perceived importance of 8 parameters on their cat's QoL, including appetite, human interaction, interaction with other pets (where applicable), desire and ability to engage in play, comfort while resting or sleeping, normal grooming activity, appropriate use of the litter box, and desire to go outdoors (when applicable). We chose these parameters based on an assumption that pet owners perceive these qualities as important for their cat's well-being. These questions used a 10-point rating scale ranging from 1 (no importance) to 10 (extremely important). The same owners were then asked to rate their level of concern regarding (1) their inability to tell if their pet is suffering and (2) their inability to know how long their pet is going to live. These questions used a 10-point rating scale ranging from 1 (no concern) to 10 (extremely concerned). The same owners were then asked a series of questions regarding administration of medications to their cats. The questions and 10-point rating scales were as follows: (1) have you ever had to administer oral medications to your cat, and if so, how difficult is it to do so (1, no difficulty; 10, extreme difficulty), (2) does the act of administering medication(s) have a harmful effect on your cat's QoL (1, no effect; 10, extreme effect), and (3) which form of medication would you rather administer (liquid, pills, injectable). The same owners were then asked to indicate their concern regarding administration of 1 medication once a day, 1 medication twice a day, 2 or more medications once a day, and 2 or more medications twice a day (1, not concerned; 10, extremely concerned). The owners were then asked 2 questions regarding hospital visits, including (1) how much stress do you think your cat experiences before and during a hospital visit (1, no stress; 10, extreme stress) and (2) how difficult is it for you to bring your cat to this hospital for veterinary care (1, not difficult; 10, extremely difficult).

The same owner was then asked the following question: “If you could give medications that would maintain or improve your cat's quality and enjoyment of life but at the same time would potentially reduce life expectancy, what would you consider to be the ideal balance between these two concerns?” This question used a 10-point rating scale ranging from 1 (low QoL but long lifespan) to 10 (high QoL but short life span). The same owner was then asked if they would be willing to trade longevity for QoL, and if so, “how much survival time would they be willing to trade to achieve comfortable QoL in their cat with heart disease?” Owners responded either “yes” or “no” to the initial question, and if they answered in the affirmative, they then selected from the following responses: 3 days, 2 weeks, 2 months, or 6 months. In addition to completing the questionnaire, respondents were asked to provide their age, sex, number of cats currently owned, and whether or not they had previously owned a cat with heart disease. The timing of when during the course of the hospital visit the protocol questionnaire was administered was left to the discretion of the study sites. Cat owners were eligible to complete the questionnaire only once, regardless of whether or not they visited the participating hospitals multiple times. The study protocol was approved by the Institutional Animal Use and Care Committees and Institutional Review Boards, as required of each participating study site. For each cat, the primary attending veterinary cardiologist provided descriptive data, including method of presentation (outpatient versus emergency), primary cardiac diagnosis, clinical class of heart disease based on the International Small Animal Cardiac Health Council (ISACHC), clinical signs including exercise intolerance, fainting, poor appetite, respiratory difficulty, and paresis/paralysis, and whether the cat was currently receiving medications. Statistical analysis was performed by PC-based software.a Descriptive statistics were calculated. Continuous and ordinal data were expressed as median values and ranges. Categorical data were expressed as frequencies. Wilcoxon sign test was used to compare owner responses to rating scale questions and P value <.05 (2-tailed) was considered significant. Logistic regression analyses were performed to evaluate factors associated with the owner willingness to trade time for QoL and for those owners willing to trade, factors associated with the willingness to trade at least 6 months of time. Two-way interactions among the main effects were investigated. An interaction term was retained based on a P value <.05. Univariate analysis was performed initially and factors with a Wald test P value <.20 were tested in the multivariate model. Factors would be retained in the model based on a Wald test P value ≤.05 or if found to be a confounder (changing model coefficients by >15%).

Results

  1. Top of page
  2. Abstract
  3. Materials and Methods
  4. Results
  5. Discussion
  6. Footnotes
  7. Acknowledgment
  8. References

Two hundred and thirty-nine cats were recruited to the study, 36 from Tufts (15%), 34 from the Animal Medical Center (14%), 29 from the University of Pennsylvania (12%), 28 from The Ohio State University (12%), 25 from Animal Care Center (10%), 22 from Veterinary Emergency Clinic (9%), 21 from Angell Animal Medical Center (9%), 23 from Veterinary Specialists of Rochester (10%), 19 from Hudson Valley Veterinary Cardiology (8%), and 2 from Ontario Veterinary College (1%). Thirteen clinicians were involved and contributed from 1 to 36 cases each. Eleven cases (5%) presented as emergencies and the remaining 228 cases (95%) were outpatients. Median age was 8 years (range 1–19 years). Fifty three (22%) cats were female and 186 (78%) were male. The primary diagnosis was provided for 233 cases, which included 167 cases (72%) of hypertrophic cardiomyopathy, 37 cases (16%) of other forms of cardiomyopathy, 6 cases (3%) of congenital heart disease, and 23 cases (10%) of other cardiac diseases. ISACHC heart failure class was provided for 233 cases. One hundred and twenty-one (52%) were in class 1, 62 (27%) in class 2a, 35 (15%) in class 2b, 15 (6%) in class 3. Seventeen of the cats (7%) had never been medicated for any reason. Seventy-eight cats (33%) were from single cat households, 71 from a household with 2 cats (30%), and 88 (37%) from a household with 3 or more cats. Respiratory distress was the most common clinical sign reported (24%), followed by exercise intolerance (11%) and poor appetite (8%). Fainting and paresis were infrequently reported in 3% of the cases each. Two hundred and twenty-six owners provided their age. The median age was 46 years (range 14–78 years). Two hundred (85%) of 235 owners responding to the questions were female and 35 (15%) were male. When owners were asked to rate their cat's QoL, the median rating was 9 (range 1–10). When owners considered their cat's QoL, the median score for importance of appetite was 10 (range, 5–10), interactions with people was 10 (range, 5–10), interactions with pets was 7 (range, 1–10), playing with toys was 8 (range, 1–10), sleeping comfortably was 10 (range, 5–10), grooming was 8 (range, 1–10), litterbox habits was 10 (range, 1–10), and desire to go outside was 8 (range, 1–10) (Fig 1). When owners rated their level of concern regarding their inability to tell if their pet was suffering, the median score was 9 (interquartile range [IQR], 6–10; range, 1–10) and their level of concern over their inability to know how long their pet was going to live was 8 (IQR, 5–10; range, 1–10). While both of these median scores would be considered high, the concern over suffering was significantly higher than the concern over life expectancy (P= .001; Fig 2). When owners were asked to rate the ideal balance between “1, Low quality of life but long lifespan” and “10, High quality of life but short life span,” the median score was 8 (IQR, 6–9; range, 3–10). Two hundred and fifteen of 230 responding owners (93%) were willing to trade survival time to achieve comfortable QoL in their cat with heart disease. Of those, 122 owners were willing to trade at least 6 months. On univariate analysis, factors associated with the willingness to trade survival time for QoL with a P value <.2 included age of the owner (P= .19) and the presence of more than 2 cats in the household (P= .09), with older owners and those with >2 cats more willing to trade. Multivariate analysis revealed neither of these factors significantly affected the owners' willingness to trade survival time for QoL. Owners of all 11 cats that were presented as an emergency were willing to trade but this variable was not used in the analysis because it predicted the outcome perfectly. On univariate analysis, factors associated with the willingness to trade at least 6 months of survival time for QoL with a P value <.2 included the Animal Medical Center (New York, NY) site (P= .002), ISACHC class (P= .05), whether the animal was medicated (P= .18), stress associated with hospital visits (P= .08), and number of cats in the household (P= .08). Multivariate analysis revealed that only site significantly affected the owners' willingness to trade at least 6 months survival time for QoL. Cats that were evaluated at the Animal Medical Center site had a 4.0 greater odds of being less willing to trade at least 6 months of survival time (95% CI, 1.7–9.4; P= .002) compared with owners of cats evaluated at other sites. The large majority of owners (222/239; 93%) had previously administered medications to their cats. When asked to assess the difficulty of medicating their cats the median score was 3 (range, 1–10; n = 221; Fig 2a). When asked to judge the effect of administering medications on their cat's QoL, the median score was 2 (range, 1–10; n = 206; Fig 2b). With regards to expressing a preference for formulation of medications, 142/234 (61%) respondents preferred pills, 69/234 (29%) preferred liquids, and 23/234 (10%) preferred injections. Owners were increasingly concerned over their ability to medicate their cats as the number of pills and dosing frequency increased (Fig 3). The median score in response to 1 medication dosed once a day, 1 medication dosed twice a day, 2 medications dosed once a day, and 2 medications dosed twice a day were 1, 2, 3, and 3.5, respectively (P < .0001), with ranges of 1–10 for all 4 choices. Owners perceived that their cat experienced a high level of stress before and during a hospital visit (median response of 8 [range, 2–10; n = 238]; Fig 4). In response to how difficult it was to bring their cat to the hospital for veterinary care, owner responses indicated a median of 4 (range, 1–10).

image

Figure 1.  Owners' assignment of the importance of various factors when evaluating the quality of life of their cats with cardiac disease. Boxes represent the interquartile range (IQR), the line within the box represents the median value, the whiskers denote the range extending out to 2 × IQR, and individual data points that were >2 × IQR are denoted as small squares.

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image

Figure 2.  Owners' responses regarding (a) difficulty administrating medications to their cat (median response, 3) and (b) perceived effect of the act of administering medications on their cat's quality of life (QoL) (median response, 2).

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image

Figure 3.  Owners' level of concern regarding potential number of medications and dosing frequency instructions to their cat with heart disease. Boxes represent the interquartile range (IQR), the line within the box represents the median value, and the whiskers denote the range extending out to 2 × IQR. Columns with different symbols indicate statistically significant (P < .05) differences between groups. Every 24 hours, once daily administration; every 12 hours, twice daily administration.

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Figure 4.  Owners' perceived level of stress experienced by their cat before and during a hospital visit (median response, 8).

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Discussion

  1. Top of page
  2. Abstract
  3. Materials and Methods
  4. Results
  5. Discussion
  6. Footnotes
  7. Acknowledgment
  8. References

The results of this study indicate that while cat owners are concerned with extending the survival time of their pet with heart disease, achieving good QoL is relatively more important. A majority of dog owners (86%) are willing to trade longevity for QoL,1 and this preference compares favorably with our results wherein 93% of cat owners responded in a like manner. Moreover, our study revealed that owners were more concerned over the ability to detect suffering than predicting life expectancy. In humans with heart disease, physical suffering is the primary determinant in the overall assessment of QoL,2 and when they perceive their pet to be suffering with little recourse to alleviate clinical signs, pet owners commonly elect humane euthanasia. Thus, in veterinary medicine, QoL is inexorably intertwined with longevity, and treatments that improve or maintain QoL should be expected to simultaneously increase survival. A previous study utilized an owner questionnaire to assess QoL in cats treated for lymphoma and found that owners' satisfaction with the chemotherapy experience was largely determined by the perceived QoL during the treatments.3 To the authors' knowledge, no validated metric for measuring QoL in cats exists in veterinary medicine. Future studies evaluating the clinical efficacy of cardiac medications should develop appropriate tools and consider including QoL assessment as an important clinical endpoint. Such tools should include aspects of QoL that are deemed most important to pet owners, including pain control, pet-owner interaction, mobility, cognitive function, appetite, and normal routines for sleeping, grooming, and socializing.3,4

Ideally, veterinary care of cats with heart disease provides both increased longevity and increased QoL; however, many commonly prescribed cardiac medications including beta-blockers, calcium-channel blockers, or ACE-inhibitors have not been shown to achieve either. In fact, anecdotal data suggest that the concomitant use of any of these agents in addition to furosemide achieves no greater longevity than use of furosemide alone.b The aim of this study was to evaluate whether cat owners regard administration of medication and visits to the hospital as potentially affecting their cat's QoL; in other words, can aspects of treatment that are relatively benign in humans negatively impact the QoL of cats? While most owners felt it was not difficult to administer oral medications to their cat, a substantial number of owners indicated that it was “extremely difficult” to medicate their pet. Most owners were not concerned with daily administration of 1 medication but the level of concern increased as the number of medications and dosing frequency increased. Thus, medications that do not improve QoL of the cat but are prescribed for potential long-term survival benefit could, in fact, be perceived as detrimental by some cat owners. A dialogue between the veterinarian and cat owner about the administration of additional medications versus the potential benefit could help identify the optimal individualized treatment plan. Moreover, our study reveals that many owners perceive hospital visits as very stressful for their cat. Medications that have a potential survival benefit but require more frequent veterinary monitoring might actually be disfavored by the cat owner.

It also is important to consider the preferences of those owners, albeit a minority, who are more concerned about longevity than QoL. While extending survival is undoubtedly a valid goal of therapy, the clinician must remain cognizant of instances where owners keep a suffering animal alive for reasons external to the welfare of the pet. An important role of the veterinarian in these instances is to “lead the client to ‘recollect’ quality of life issues.”5 The veterinarian likely can provide the best care for an individual cat by specifically inquiring about preferred form of medication, discussing evidence for potential benefit, risk of complications, need for monitoring, and tailoring the treatment plan based on appropriate owner priorities. A consistent approach to QoL assessment that includes appetite, ability to sleep comfortably, litter box habits, and interaction with the owner(s) can facilitate useful discussions between the cat owner and veterinarian. Specific discussions to identify these and other important factors might be a useful means to gauge a cat's QoL and “success” or “failure” of treatment as disease progresses.

Our results indicate that the reasons why most cat owners prefer quality over quantity of life are multifactorial and complex. On univariate analysis, older owners and those with >2 cats in the household were more willing to trade. The reasons for this finding are unknown, but could involve the fact that older owners have a greater likelihood of dealing with their own health and QoL issues,6 or that owners are better able to diminish the loss of a pet through the reassurance of having others in the household. With respect to an owner's willingness to trade 6 months of time, on multivariate analysis, study site was the only variable identified, with owners of cats presenting to the Animal Medical Center site being 4.0 times less likely to trade 6 months of time for QoL. The reasons for this finding are not immediately clear. The Animal Medical Center site represents a large referral center within a busy urban environment (ie, New York City); however, other study sites, such as Angell Animal Medical Center and University of Pennsylvania, are in similar urban environments (Boston and Philadelphia, respectively), yet clients of these institutions failed to demonstrate the same preference. It is tempting to speculate that sociodemographic factors such as ethnicity, economic status, religion, and other variables, which play a role in personal end of life preferences,7–9 extend to choices made for one's pets. On average, residents of the Manhattan borough of New York City have higher median incomes and smaller households and family sizes compared with the rest of the United States,10 and perhaps the financial ability to provide long-term care or the presence of fewer human companions influence a cat owner's desire to prolong life.

To quantify owners' individual preferences regarding their cat's health care, we used a modification of the time trade-off tool,11 which has been used in human medicine since the 1940s. Using this method, respondents are asked to choose between a length of time in their current state of health or a shorter time in perfect health. In people with heart disease, the time trade-off tool typically reveals a bimodal distribution, with the majority of patients being either unwilling to trade any survival time or willing to trade the maximum amount of survival time offered by the survey, with few respondents seeking a compromise between the 2.12 In human patients, willingness to trade QoL for survival time was associated with lower peak oxygen consumption, high jugular venous pressures, dyspnea, and low QoL questionnaire score.13 In our study, willingness to trade time was not associated with ISACHC heart failure class. In general, patients with severe disease that required hospitalization were willing to trade survival time; however, this preference tended to change in favor of longevity as they were discharged from the hospital.13 In our study, while all owners whose cats presented as an emergency were willing to trade, we did not repeat the questionnaire at patient discharge, and further studies are indicated to determine if preferences change with onset of clinical signs or as disease progresses. This study has several limitations. The study sites were limited to university and referral hospitals, and cat owners seeking specialty care may demonstrate different preferences from those visiting a primary care facility. Owners were asked to complete the questionnaires having received varying degrees of information regarding the diagnosis and condition of their pet. For instance, owners sometimes completed the questionnaire before discussion of results from that particular hospital visit with the attending veterinarian. In other cases, owners completed the questionnaires in conjunction with input from friends or family members that accompanied them, resulting in a group opinion regarding the issues in question. The questionnaires were administered at a single point in time and we did not evaluate whether owner perceptions and priorities would change along with the natural history of their cat's disease. The great majority of cats involved in our study presented as outpatients, and the results of our study might not be applicable to owners of cats with emergent clinical signs. Finally, the results of our study are limited to owners of cats with heart disease and might not necessarily apply to owners of cats with other disease conditions. In conclusion, owners of cats with heart disease are more concerned with maintaining their cat's QoL than prolonging their survival time. Owners consider administration of multiple medications as well as hospital visits as concerning and stressful, and these variables may be perceived as negatively impacting their cat's QoL. Most owners, independent of age or sex, were willing to trade longevity for QoL, however, the impact of geographic locale warrants further study. Our results suggest that discussions between the owner and veterinarian regarding perceptions and priorities of QoL will help achieve optimal veterinary care. Further study should address creation of standardized tools to measure QoL and incorporation of QoL endpoints into studies seeking to ascertain the clinical value of veterinary interventions in cats with heart disease.

Footnotes

  1. Top of page
  2. Abstract
  3. Materials and Methods
  4. Results
  5. Discussion
  6. Footnotes
  7. Acknowledgment
  8. References

aStata version 8, StataCorp, College Station, TX

bFox PR. Prospective double-blinded multicenter evaluation of chronic therapies for feline diastolic heart failure: Interim analysis. J Vet Cardiol 2003;17:398 (abstract)

Acknowledgment

  1. Top of page
  2. Abstract
  3. Materials and Methods
  4. Results
  5. Discussion
  6. Footnotes
  7. Acknowledgment
  8. References

The authors thank Gordon Peddle, Carolyn Michel, and Lynne O'Sullivan for their assistance.

References

  1. Top of page
  2. Abstract
  3. Materials and Methods
  4. Results
  5. Discussion
  6. Footnotes
  7. Acknowledgment
  8. References