Get married, live longer?

Being someone who is not married – though I’ve been engaged for six years! – I see online a lot of articles discussing marriage. And there’s a good reason for this: the current trend in society today is away from marriage. Fewer people are getting married, and they are waiting longer to get married. So with that trend in mind, how can you convince people into wanting to get married, and do so sooner? Oh, I know! Convince them that if they don’t get married, they’ll die sooner.

Well such seems to be the trend on romance sites. Ladies, if your guy won’t commit, tell him that unless he gets married, he won’t live nearly as long. If only it were that simple.

The recent study published in the American Journal of Epidemiology is not the first study published attempting to link a correlation between marriage and mortality. When looking through a scientific paper, the limitations of the study should always be discussed and acknowledged. If they don’t recognize the limitations of the study, then there is an air of bias to that study that calls the rest of the paper and its conclusions into question.

A 2009 study1Dupre, Matthew, et. al., "Marital Trajectories and Mortality Among US Adults". Am J Epidemiol. 2009 September 1; 170(5): 546–555. Published online 2009 July 7. doi:  10.1093/aje/kwp194 published in the same journal, acknowledged the various limitations of attempting to study the correlation between marriage and mortality:

Our results reaffirm the fact that married persons live longer, and they further demonstrate that the health benefits of marriage and the detriments of marital dissolution are more complex than previously shown. We found that every facet of a marital trajectory was associated with mortality. As anticipated, the mortality risks associated with current marital status were highly significant.

The health benefits of marriage and detriments of divorce are more complex than previously shown. In other words the question is not so cut and dry. Further in the same paragraph, the authors note:

In either case, marital status had the least robust association with mortality compared with other trajectory measures once differences in risk were taken into account.

In other words, marital status alone is not what matters. Yet, this is all that most people seem to be focusing on. As this study notes, as well, the question is complex. Boiling it down to "get married, live longer" is disingenuous at best, fraudulent at worst. Further the age at which you get married is also a contributing factor. Marry younger, die sooner, marry later, live longer, seems to be a trend observed in the 2009 study:

Our analysis demonstrated that the most distal characteristic of marital history—age at first marriage—had lasting consequences for mortality. Results showed that marrying as a teenager increased the risks of dying by 56% for men and 38% for women.

Somewhat surprisingly, late marriages significantly reduced men’s mortality by approximately 20% compared with the majority of men who married between ages 19 and 25 years. Moreover, there was no evidence to suggest that postponement of marriage enhanced men’s socioeconomic resources as a mechanism to reduce mortality. To our knowledge, this study is the first to document a significant relation between late marriage and mortality, and we await further studies to confirm this finding.

The last sentence of this quote is the most important: the authors believe their study to be the first to note a positive correlation between marrying later and living longer. As such that observation should be considered only preliminary.

But all of the studies still show that divorce could lead to a lower life span. Should we outlaw divorce for this reason? Absolutely not. But at the same time, the 2009 study seemed to show something else that is of note: it’s not that you’re married, it’s how long you’re married that matters:

Marriage duration is the least studied component of marital life; however, in this study, it was one of the most robust factors contributing to mortality differentials. Mortality decreased significantly as the number of years of marriage increased, and the benefits were greatest for adults who accumulated 40 or more years of marriage compared with those with fewer than 20 years. These findings are especially significant given that a third of respondents with 30 or more years of marriage—and more than a quarter of those with 40 or more years—had at least one marital disruption. Therefore, it is plausible that attaining long durations of marriage can be as protective against mortality as maintaining a stable marriage. However, more research is needed to validate this claim.

I love how the authors of this study are very willing to cite the limitations. Again, this correlation is not well established, but this 2009 study shows a positive correlation.

The one thing on which most of these studies remain focused is the marital status, not the relationship itself. Is it just as possible that a stable, long-term relationship could have the same protections against mortality even if that couple is not married? I see no reason to think it could not, but I do not believe there are any studies that actually seek to answer this question. And the one place where such a question could be studied is the homosexual community.

But then there’s one question not yet addressed: why do those in a stable, long-term marriage have a greater tendency toward longer life? The 2009 study addressed this question as well:

The healthful effects of marriage duration for men were largely reduced by behavioral factors and moderately reduced by socioeconomic resources and health status. This finding supports the argument that marriage length protects men’s health by providing a lasting supportive environment that encourages reduced tobacco use and alcohol consumption, improved diet and exercise, and utilization of preventive care to detect and treat illnesses. Women’s hazard ratios were attenuated most by socioeconomic factors and less by behavioral and health factors. These findings support the argument that long marriages protect women’s health by increasing financial stability, wealth, and the health-purchasing resources needed to access quality health care, pay for costly treatments, and afford prophylactic lifestyles.

Unfortunately the recent 2011 study is locked behind a paywall and is not available anywhere online for free, to the best of my knowledge. That study in question is titled "The rising relative risk of mortality for singles: meta-analysis and meta-regression", and was published in the August 15, 2011, edition of the American Journal of Epidemiology.2Am J Epidemiol. 2011 Aug 15;174(4):379-89. Epub 2011 Jun 29. The study title shows that this recent study is nothing more than a meta-analysis. For those who don’t know, a meta-analysis is a study by which several researchers went back through the published literature looking for all studies relevant to a question and, in examining all of those studies, attempt to summarize the current consensus regarding that question. But meta-analyses raise another important question: what specifics or limitations get lost in the process?

There have been plenty of studies on the correlation between marriage and mortality. Without being able to take the recent study into account, what kind of conclusions can be drawn from this? Not much.

First, longer marriages tend to be happier marriages, so seeing the 2009 study show a negative correlation between longer marriages and mortality is not surprising. Does this mean that married individuals should just fight it out and continue with their marriage? Not if they are unhappy as they may be doing themselves more harm than good.

That is the single fundamental limitation with any study on this question. While it may be easy to assume that longer marriages are happy marriages, this may not always be the case. If they belong to a belief system that frowns on divorce or live in a segment of our society where divorced couples or divorced individuals are treated with less esteem than their married counterparts, the individuals in question may decide to stay in an unhappy marriage just to avoid the social consequences of divorce. This doesn’t mean their marital status automatically means they live longer.

And that is the biggest takeaway from all of the current studies: marital status is not what matters. Instead what matters is the quality of the relationship in question. If the relationship is unhappy, it matters not whether you are married. If you’re in an unhappy, stressful relationship full of misery and strife, you’re probably just as likely, if not more likely to die younger than your unmarried counterparts.