2% higher mortality in private hospitals vs. public hospitals according to new study

New research suggests that people treated in private hospitals are slightly more likely to die than patients cared for in public ones.

Researchers from three universities in the United States and Canada studied the medical records of nearly 40 million people treated in American hospitals over a 13-year period.

The research, published in the Canadian Medical Association Journal, shows that 2% more private-hospital patients had died than public ones.

The researchers have suggested the higher mortality rate may be because hospitals run for profit in the US have to pay dividends to shareholders and tax, and have less money to spend on patients.

They say their findings should discourage Canada from privatising its healthcare system.

From the newsroom of the BBC World Service --------------------------------------------------

From "A systematic review and meta-analysis of studies comparing mortality rates of private for-profit and private not-for-profit hospitals" by P.J. Devereaux et al., published in the Canadian Medical Association Journal May 28/2002 issue

Our systematic review identified 15 observational studies that compared private for-profit with private not-for-profit hospital mortality. These studies uniformly met quality criteria regarding adjustment for potential confounders, in particular, patients' severity of illness or surrogate markers of severity of illness, and complete accounting of deaths. Our pooled analysis of the adult population studies demonstrated that private for-profit hospitals were associated with a statistically significant increase in the risk of death.

We are aware of 2 earlier reviews in this area. The New York Academy of Medicine has reported a qualitative review that compared access, costs, quality of care, education and research in for-profit and not-for-profit hospitals, managed care organizations and nursing homes.47 This review only included 4 of the 15 studies we identified and reached the general conclusion that the studies evaluated provided no clear indication as to the superiority of either hospital system regarding the quality of care and health outcomes.47 The second review focused on the public purchasing of private surgical services.48 This qualitative review identified 7 of the 15 studies we included and reached the general conclusion that more research was needed.

We undertook multiple strategies to identify studies, including searching 11 bibliographical databases, and found a number of studies not included in earlier reviews (see preceding paragraph). We masked study results before determining study eligibility. Our agreement on study inclusion was high as was our agreement during data abstraction. We were also successful in confirming and obtaining information from authors (see Appendix49). We were able to identify 15 studies with very large sample sizes that adjusted for potential confounders.

Our systematic review has several limitations. The most important is that we were unable to identify any RCTs. It is unlikely that RCTs will ever be undertaken to study this question, thus the strongest feasible design for addressing our question is observational. However, all 15 studies we identified did adjust for potential confounders, including teaching hospital status and markers of patients' severity of illness.

A major threat to the validity of observational studies is residual confounding. Is it possible that there are factors other than private not-for-profit hospital status that explain such institutions' lower mortality rates? One such factor could be teaching status, because a much higher proportion of private not-for-profit than private for-profit hospitals are teaching hospitals. However, 3 of the studies conducted analyses that excluded teaching hospitals altogether and found a statistically significant increase in mortality in the private for-profit hospitals (RR 1.01, 1.05 and 1.05).16,21

Inevitably, large administrative databases have a limited ability to adjust for disease severity. Is it possible that patients in private not-for-profit hospitals were, on average, less sick? Most of the studies considered here used the Health Care Financing Administration (HCFA) database that includes data on all US hospitals that serve Medicare patients and generates risk-adjusted mortality rates that are highly correlated with detailed clinical risk–adjusted mortality rates.33 Moreover, in the studies that reported both unadjusted and adjusted results for disease severity, the adjusted analysis consistently led to effect estimates that were more favourable to the private not-for-profit institutions, suggesting that private not-for-profit hospitals serve a population of patients with greater disease severity.13,14,16,22 Under these circumstances, we would anticipate that residual confounding would make the private not-for-profit institutions look worse, rather than better, than the private for-profit institutions. These considerations suggest that, if anything, our results may represent an underestimate of the potential increase in mortality associated with private for-profit hospital care.

Ideally, studies would have adjusted for, or considered as explanatory factors, other variables for which data were not available. These variables include whether the physicians wre hospital employees or corporate employees, or independent contractors, and their relationships with local health maintenance organizations. Finally, studies have done little to adjust for the proportion of Medicare patients versus privately insured patients in the institutions being analyzed. With respect to this last variable, however, it is likely that for-profit hospitals attracted a larger proportion of privately insured individuals. If this is the case, private for-profit providers would have more resources available, and one might expect a "spillover" effect of improved care to Medicare patients. To the extent that this is the case, our pooled estimate again biases the results against the private not-for-profit institutions.

When studies show important differences in results, rigorous systematic reviewers explore the data to see if they can identify cogent explanations for the differences. How they should proceed if they fail to find an explanation for the differences remains controversial. Some argue that under these circumstances, pooling is inappropriate. Others argue that clinicians, and in this case health policy-makers, must still make decisions, and their decisions should be driven by the best available estimate of treatment effect.50 In the presence of unexplained heterogeneity, while inferences associated with pooled estimates are weaker, these estimates nevertheless provide the best estimate of the average effect, and thus constitute useful information for decision-makers.

The studies we pooled used similar methods to examine similar populations. Moreover, one does not require a pooled analysis to generate concern about the impact of for-profit status on hospital mortality: 7 studies provided statistically significant results that favoured lower mortality in private not-for-profit hospitals, whereas only one study had a statistically significant finding in the opposite direction.

We have no satisfactory explanation for the one study that demonstrated a statistically significant lower risk of death in private for-profit hospitals.19 Other large studies that used data from the same database before and after this study reached the opposite conclusion.14,16,17,20,21,23 We contacted the authors of this study and asked them to undertake further analyses to determine what may have accounted for this discrepant finding.19 The authors declined our request.

Considering these issues one might feel concern that the profit motive of private for-profit hospitals may result in limitations of care that adversely affect patient outcomes. Our results suggest that this concern is justified. Studies included in our review that conducted an initial analysis adjusting for disease severity, and another analysis with further adjustment for staffing levels, support this explanation for our results. The private for-profit hospitals employed fewer highly skilled personnel per risk-adjusted bed.14,20 The number of highly skilled personnel per hospital bed is strongly associated with hospital mortality rates,14,17,20 and differences in mortality between private for-profit and private not-for-profit institutions predictably decreased when investigators adjusted for staffing levels. Therefore, lower staffing levels of highly skilled personnel are probably one factor responsible for the higher risk-adjusted mortality rates in private for-profit hospitals.

Given the differences in the organization of the Canadian and US health care systems, one might question whether our results can be applied to Canada. The structure of US health care has, however, shifted dramatically over time. With the exception of a single study, the results are remarkably consistent over time, suggesting that the adverse effect of private for-profit hospitals is manifest within a variety of health care contexts. Furthermore, whatever the context within which they function, for-profit care providers face the problem of holding down costs while delivering a profit. One would, therefore, expect the resulting problems in health care delivery to emerge whatever the setting. Finally, should Canada open its doors to private for-profit hospitals, it is the very same large US hospital chains that have generated the data included in this study that will soon be purchasing Canadian private for-profit hospitals. In summary, we think it plausible, indeed likely, that our results are generalizable to the Canadian context.

The Canadian health care system is at a crucial juncture with many individuals suggesting that we would be better served by private for-profit health care delivery. Our systematic review raises concerns about the potential negative health outcomes associated with private for-profit hospital care. Canadian policy-makers, the stakeholders who seek to influence them and the public whose health will be affected by their decisions should take this research evidence into account.

-------------------------------------------------- http://www.cmaj.ca/cgi/content/full/166/11/1416

Commentary published in the Canadian Medical Association Journal May 28/2002 issue

The Canadian health care system is in the throes of yet another of its periods of agonized introspection. The debate is already polarized, and the rhetoric heated. In this issue (page 1399),1 a provocative and important study by P.J. Devereaux and colleagues will further raise the temperature of our national medicare discourse.

The authors have systematically reviewed and pooled the results of 14 US studies that compared short-term mortality outcomes for elderly patients admitted to private, for-profit hospitals with those for elderly patients admitted to private, not-for-profit hospitals. After pooling, the authors concluded that there was a clinically meaningful (relative risk 1.02) and statistically significant (p = 0.02) increase in 30–90-day mortality among patients admitted to private, for-profit hospitals

This study should serve ideally as useful grist for the ongoing international debate about the governance and management of health care systems, and it should spark some interesting arguments about the methods used by the authors.

On a pessimistic note, however, this commentator also predicts the following responses. The article will provoke domestic headlines and editorials. Left-leaning proponents of the status quo will call on Mr. Romanow, head of the Commission on the Future of Health Care in Canada, to defend Canadian medicare against privatizing infidels within and without our borders. The Right will claim that the study is utterly inapplicable to Canada and renew their call for Medical Savings Accounts, deductibles, copayments and other articles of faith in the neo-conservative canon. Meanwhile, US newspapers and researchers will take brief notice of this study and then shrug it off.

Such responses are not just a function of ideologies. The study lends itself to competing interpretations. In that spirit, let me put forward the following contradictory propositions and defend them.

2. The study is seriously limited in its generalizability to Canada, but it contains valuable lessons for our health care debate.

What the authors have done is far from typical in meta-analysis of clinical research data. In meta-analyses of treatment trials, the intervention under study is generally well-defined and consistent across the trials. Here, for-profit ownership of hospitals is the "intervention." The data are derived from a series of observational studies, not a set of experiments or trials in which randomization helps ensure that confounders are balanced within and across centres. Although each study includes different patient populations, the same hospitals are presumably included multiple times if their for-profit and not-for-profit status is constant. Hence, unmeasured hospital-level and provider characteristics may be repeatedly confounding the results. To their credit, the authors have tried to control for other confounding factors at the institutional level, such as teaching status or multihospital networks. However, these remain broad-brush characterizations.

To deal with the inevitable selection biases that would see sicker patients going to not-for-profit institutions, the authors have focused on the results of studies that adjusted for the expected mortality or comorbidity, or both, of the patient populations. To that end, they used the coefficients from multivariate models published in these articles and deduced the actual proportions of individuals who would have been dead and alive if one could control for other factors. However, the studies differ in the variables used for modelling purposes, the methods of model construction and even whether or not for-profit or not-for-profit status was the variable of principal interest rather than one potential confounder in a model oriented to other ends. Data aggregation has therefore created something of a tossed salad of patients, institutions, variables and outcomes. It is perhaps not surprising that, despite pooling data from 38 000 000 patients, the level of statistical heterogeneity in the findings was as significant as the adverse effect associated with for-profit ownership (both p = 0.02).

One potential source of variation in the results is the degree to which "managed care" has expanded in different US medical marketplaces. Among the studies, the analysis by Mukamel and colleagues2 is notable for its close attention to the role of HMO market penetration and competition as a factor in hospital performance. Conservative colleagues will doubtless highlight the fact that this study alone showed for-profit status to be associated with significant mortality advantages on multivariate analysis. To that I would say only, not so fast. According to one of the study authors (Dr. Jack Zwanziger, School of Public Health, University of Illinois: personal communication, 2002), the directionality of the for-profit term in their multivariate model may well be a function of the other variables included in their analysis. For example, many of the for-profit hospitals were concentrated in the Pacific region during the period of that study. Hospital mortality was also much higher there. In contrast, there were comparatively few for-profit hospitals in New England and the Mid-Atlantic United States along with much lower short-term mortality. Add "region" to the model (as the authors did), and the for-profit term may be driven toward a nonintuitive weight and direction. Indeed, this study probably accounted for much of the heterogeneity in the results and almost certainly reduced the level of the not-for-profit effect.

This caveat underscores the fact that the authors may, if anything, have weakened their case by generating a pooled estimate of the for-profit effect. Even without aggregation of the data, there are 3 compelling reasons to believe the overall result.

First, the finding of excessive mortality associated with for-profit hospitals recurs in one study after another. It also recurs in most of the studies that were excluded and is evident with multiple modelling techniques.

Second, these studies are not clustered in one time or place. Excess mortality associated with for-profit hospitals is evident in separate comparisons covering most of the United States, over more than a decade in which the US health care system underwent a major transformation in finance and organization.

Third, the authors' secondary findings lend strong plausibility to the overall conclusion. For example, individual study findings are consistent with the literature showing outcome advantages for teaching hospitals.3 The authors also astutely separated out variables that might be under the control of hospital administrators and found that adjustment for staffing levels diluted the advantage of the not-for-profit hospitals. Other research suggests that, ceteris paribus, excessive cuts to the number of skilled bedside nurses lead to an increase in adverse in-hospital outcomes.4,5

Let us turn to the second issue: generalizability. A skeptic might argue that the study findings are applicable to Canada only under the following conditions: we eliminate universal health care coverage, retain public insurance only for the poor and the elderly, segment the rest of the market with competing private plans that leave millions uninsured or underinsured, create a large for-profit health care sector, promote managed care models with risk-sharing, place a large percentage of physicians on salary in for-profit and not-for-profit organizations, allow elderly people covered by our mandatory public plan to purchase supplemental insurance on a self-financed basis, jettison some of our social services, re-create US regional variation in hospital care and outcomes and, not least, assimilate a health care culture that mixes unparalleled technological capacity and intervention with inexplicable neglect!

On a more serious note, the study was obviously not designed to address many of the questions about private sector involvement that go the heart of our national medicare debate. Is it advisable for governments to build public hospitals with private capital, or are we simply mortgaging our future? How much of the development and management of health information services should be contracted out to private industry? How can we reform our patchwork and partially privatized system of pharmaceutical benefits?

Today, Canada is the only industrialized nation that prohibits private insurers from covering any publicly insured health services. Public opinion polls suggest that Canadians have mixed feelings about parallel private insurance. The work of Devereaux and colleagues, however, sheds no direct light on the risks and benefits of allowing for-profit insurers to compete with the public prepayment system. It describes a situation in which private, for-profit hospitals operate as contractors to a public insurance scheme for elderly people. In theory, Canada could choose to adopt the converse position whereby our not-for-profit institutions would draw new revenue streams from private insurance to support their broader social mission.

That said, there are lessons to learn from the timely work of Devereaux and colleagues. Does anyone still want to contract out large segments of our publicly financed health care system to for-profit US hospital chains after reading this article? I hope not. In my view, these findings should also help Canadians re-embrace the core concept of a universal health care system in which the vast majority of services are provided by non-profit institutions with public accountability. Beyond that affirmation, let the medicare debate continue.

Garbage in, garbage out. It's fairly apparent that the authors have a drum to beat about socialized medicine, then went out on a fishing expedition to try and find statistics to fit their preconceptions. There are a lot of reasons mortality might be higher in private hospitals, among which are sicker patients going to private hospitals, less sick patients admitted and kept longer in public hospitals because of social reasons. I can tell you, having worked in both kinds of hospitals, the bureaucracy makes delivering care frustrating, but I will take my chances in a for profit facility every time. I have no problem with paying more money to places which need to maintain a good reputation and have an incentive to do a good job...making money. In many public hosptials, there is little incentive except to show up among the ancillary staff.

I agree with your points, you must have been typing when I was reading. Meta-analyses are notoriously difficult to interpret and only as good as the individual studies that make them up (we are told nothing about the methods of the individual studies). To blame the difference in mortality on the shareholders expecting a profit is quite a leap to a conclusion as no study tested for that as a variable. As you say, the researchers most likely had a desired conclusion in mind before they undertook their analysis.

I've read enough of this to know that it's clearly and unashamedly politically motivated.

Why is there an increase in mortality in for-profit institutions? Typically, investors expect a 10%–15% return on their investment. Administrative officers of private for-profit institutions receive rewards for achieving or exceeding the anticipated profit margin. In addition to generating profits, private for-profit institutions must pay taxes and may contend with cost pressures associated with large reimbursement packages for senior administrators that private not-for-profit institutions do not face. As a result, when dealing with populations in which reimbursement is similar (such as Medicare patients), private for-profit institutions face a daunting task. They must achieve the same outcomes as private not-for-profit institutions while devoting fewer resources to patient care. My response to this would be: Why wouldn't private hospitals have the incentive to keep patients longer (i.e., keep the beds filled and keep utilization high)? And if health care costs were driven by market forces instead of by the government (which pays about half of all medical costs), the private hospital could try to charge more. Those who feel it's worth it would pay more; those who don't see the added value would go to a different type of hospital.

Also note that private for-profit hospitals are more likely to be the source of breakthrough research, which improves life expectancy for all, including the other hospitals who eventually glom onto it.

The private for-profit hospitals employed fewer highly skilled personnel per risk-adjusted bed...a wee bit disingenuous, since private hospitals usually don't "employ" physicians but give them privileges to admit and care for patients, whereas public hospitals will actually hire and pay physicians on staff - the number of physicians actually available per patient is probably greater in the private hospitals...there've been lots of stories of patients fleeing Canada to get treatment in the US - kind of ironic that our problem with increased mortality in private hospitals here may be exacerbated by seriously ill Canadians who couldn't or didn't want to wait for treatment there.....

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