The researchers compared patients who were currently married to those who were not married (divorced or widowed or always-single). That last sentence right there tells you something essential about the research. This is a study from which definitive causal conclusions can never be drawn. No matter how many stories you may have read about this research suggesting that the married patients did better because they were married, none of them had any sound scientific basis for making that claim.
Most of the stories I read did not just proclaim that “married cancer patients live longer” (that exact headline is from the New York Times – I’ll critique their story in detail later); they went on to tell us why that happened. Most explanations pointed to social support and nagging (though they did not use that N word) – married patients have a spouse to make sure they get to the doctor quickly and who support them as they deal with the disease; single people, the hackneyed story goes, don’t have anyone.
Now here’s something that none of the media reports mentioned: All of the suggested explanations were just guesses. Social support was not measured. Nagging was not measured.
If you want to know more of the details of the study, read the next section. Otherwise, skip to the following section where I resume making fun of all of the bad reporting about it in the media, and most embarrassingly, in an editorial that appeared in the journal that published the original research (Journal of Clinical Oncology). The authors actually did include some of the most important caveats in their article, but what fun would it be for the media to admit that marriage may have had nothing to do with the findings?
The Details of the Research
(The original article may be either unavailable in its entirely or behind a pay wall. If you cannot access it, the best summary I found is this one from the U.S. National Library of Medicine, which spells out the most compelling alternative explanation to the one you heard so often in the media.)
The National Cancer Institute maintains a huge database of information on the incidence, treatment, and survival from cancer. The researchers examined data from more than 700,000 people 18 and older who had been diagnosed between 2004 and 2008 with one of the 10 deadliest cancers.
Controlling for age, sex, race, education, household income, and rural vs. urban residence, the researchers found that unmarried patients who were first diagnosed were more likely to have a cancer that had spread than were the currently married patients.
Next, they looked only at those 500,000+ patients whose cancer had not spread. They determined whether the patients had gotten the treatment (either surgery and/or radiation – no information on chemotherapy was available) considered definitive for their type of cancer. They found that after adjusting for the demographic factors as well as the tumor and nodal stage, the married patients “were more likely to undergo definitive surgical and/or radiotherapeutic management” than the unmarried patients. (The authors suggested that “the most likely reason is that married patients have better adherence with prescribed treatments than unmarried patients.”)
Finally, survival rates were analyzed as of about 3 years after the diagnosis. Married patients were less likely to have died from their cancer than were the unmarried patients.
The currently married patients also fared better than the unmarried patients when they were compared to each category of unmarried people (divorced, widowed, always-single) and not just when all of those subgroups were combined.
Finally, all three of the supposed advantages of marriage were greater for the men than for the women.
Did You Notice the Problems that All of the Media Stories – and the Editorial in the Medical Journal – Missed?
The story being told about the findings of this study is that married people with cancer fared better than unmarried people because they were married, and marriage comes with benefits such as social support and encouragement to get to the doctor sooner.
The key question is: What other explanation is possible? Is there a different reason why married people might seem to fare better in the ways measured in this study?
Here’s another hint. To claim that cancer patients do better because they are married is to say that if single people would get married, they would do better, too. Another implication of that claim is that if only the divorced people had stayed married, they too would be more likely to survive cancer. Do you buy that? If not, what does that tell you about how to think about the results?
A Few Alternative Ways of Explaining the Study
#1 Married people have more money
There is plenty of evidence that married people are economically advantaged over single people. They have the benefit of financial favoritism built right into federal laws. (That’s one of the reasons motivating the advocacy of official, legal same-sex marriage.) Single people are also targets of economic discrimination. For example, single men are paid less than married men even when they have been on the job the same number of years with the same level of accomplishments, and even when they are twins.
The authors did take household income into consideration but economic assets include more than just income. The greater wealth of married people could account for their getting to the doctor sooner, getting the best available treatment, and being more likely to survive their cancer.
#2 Married people have more access to health care
With more money comes more options for high quality health care – or any health care at all. Even apart from differences in wealth, though, there are differences in access to health insurance. For example, married people sometimes have access to health insurance through their spouse’s plan. Single people do not.
If single people had as much money and as much access to health insurance as married people, maybe they would fare just as well as married people when struck by cancer.
#3 Doctors and nurses discriminate against single patients
In Singled Out, I reviewed research on discrimination against single people by medical professionals. In a particularly telling study, physicians admitted that they provided better care and more complete care to patients who had supportive families than to those who seemed to be alone. What’s more, they said that other doctors, nurses, and staff also did the same.
If doctors provide better quality care to their married patients than to their single patients, then perhaps it should come as no surprise if married people show up at their doctors’ doorsteps sooner, if they are more likely to get the definitive treatment, and if they are more likely to survive their cancers.
More evidence for this explanation comes from a series of studies just published a few months ago in Sweden. In a study of patients with newly metastasized cancer, those who were living alone were prescribed less combination chemotherapy and surgery than patients who were not living alone. In another study in which Swedish oncologists were interviewed, the doctors said that they worried that patients living alone did not have social support, and so they ordered less chemo for them.
#4 Married people and single people are different people – any way that they differ, other than in marital status, could explain differences in health outcomes
The authors found that in their dataset, the married patients were younger than the unmarried patients and they had higher incomes and more education. They controlled for those factors statistically, so perhaps those particular factors do not explain the results, but any other differences between the two groups might.
Consider, for example, that some of the unmarried patients may have been single-at-heart (scroll down after clicking). They are people who live their best and most meaningful lives as single people. They do not want to be married. If people who are single-at-heart were badgered into getting married (perhaps in part by media stories telling them that if they stay single, they will die of cancer), do you really think they would be healthier?
Or say you are married and miserable. You want to get divorced but now you wonder whether transitioning into an unmarried state will kill you. Seriously?
There’s another difference between always-single people and married people that has long intrigued me. Single people value meaningful work more than married people do. It is a difference that shows up even in prospective studies in which people are first asked about their values in high school. Those who will stay single already value meaningful work more than those who will marry.
If single people value quality of work more than married people do, then maybe on the average, they value quality of life more, too. Suppose you knew that if you went to the doctor more often, and – if diagnosed with cancer – you submitted to every version of slashing and burning and poisoning that anyone recommended, you would live a few years longer? Now suppose your choice was to skip all that and live your life as fully and freely as possible, outside of hospitals and doctors’ offices? I have never been faced with that choice, but I think I would be very tempted to choose the latter. That’s not an indication of valuing life less but of valuing quality of life more. For cancers that are especially deadly, such as the pancreatic cancer that runs in my family, the odds that any treatment will be successful are slim.
Now about All that Social Support that Married People Supposedly Get
The belief that married people are interpersonally connected and socially supported, whereas single people are isolated and “don’t have anyone,” is a myth. It is a stereotype that has been debunked by a variety of studies with a variety of research designs. (Here are some of them – scroll down after clicking the link.)
There is also some evidence to suggest that a husband may not be such a great source of support for women with cancer, and that friends may well be. Studies of women with breast cancer have shown that husbands are, on the average, not very good at relieving women’s stress or helping them recover more quickly (Bolger et al., 1996). But if those women have supportive friends, then it did not matter if their husbands were not supportive – they could still cope reasonably well with the help of their friends (Manne et al., 2003).
Remember, too, that in the study in question, no supportive behaviors were monitored or measured, and neither were any coping behaviors. We really don’t know if the married people got more support than the single people did, whether they complied with the recommended medical regimen more, or anything else.
I am going to write one more post about this study, which you will be able to find here by the end of the week. In it, I’ll provide examples of how serious media sources and even an academic journal offered misleading descriptions what the study really did show. I’ll show you exactly what they said, and then tell you what I think they should have said instead, or in addition. I will also share one good thing about the research and the reactions to it. [Here it is.]
[Note: Thanks to Alan, Jeanine, and Erin Albert for sending me links and questions about this study. And special thanks to Mona Bjork; when she read my first post about this study on a different blog, she sent me the information about the Swedish study showing that doctors prescribe less treatment for singles living alone. I hadn’t known about that.]