Don’t Dismiss the Poor Quality of Life in Lyme Disease

Lyme disease quality of life is often underestimated in research. A recent Clinical Infectious Diseases study concluded that both mental and physical health scores improved to average over time, regardless of disease stage or severity at diagnosis. [1]

However, the authors excluded participants with pre-existing comorbidities and symptoms similar to Post-Treatment Lyme Disease Syndrome (PTLDS). [2]

How Study Design Affects Lyme Disease Quality of Life Findings

Studies that exclude patients with persistent symptoms introduce ascertainment bias and may underestimate Lyme disease quality of life.

Lyme disease patients enrolled in the NIH-sponsored natural history study were much healthier than those included in Lyme disease clinical trials.

Ascertainment bias is the systematic failure to represent equally all classes of cases or people supposed to be represented in a sample.

Comparing Quality of Life Across Lyme Disease Studies

The quality of life (QOL) at first visit in the CID study was 45.6 for the Physical Component Score (PCS) and 47.3 for the Mental Component Scale (MCS). [1]

The SF-36 scores range from 0 to 100, with higher scores representing better health. The expected scores for a healthy population are 50 for both PCS and MCS. PCS reflects physical functioning, pain, and general health, while MCS reflects vitality, emotional health, and social functioning.

In contrast, clinical trials by Klempner, Fallon, and Berende reported significantly lower PCS scores of 33, 37, and 31, respectively. [3–5] For comparison, PCS scores in cancer, diabetes, and depression are 41, 42, and 45.

Similarly, MCS scores in these trials were 39, 43, and 37, compared with 37, 41, and 48 in cancer, diabetes, and depression.

Why Lyme Disease Quality of Life May Be Worse Than Reported

A Johns Hopkins study that included patients with comorbidities and PTLDS-like symptoms found significantly lower quality of life. Baseline scores were lower and declined further at six months compared to patients without PTLDS.

Despite treatment with a three-week course of doxycycline, 36% of patients developed PTLDS. At six months, 36% reported fatigue, 20% widespread pain, and 45% neurocognitive difficulties. [6]

The marked differences between study populations highlight how ascertainment bias can lead to underestimation of Lyme disease quality of life.

Clinical Implications

This bias may help explain why persistent symptoms are sometimes dismissed in guidelines. “In many patients, post-treatment symptoms appear to be more related to the aches and pains of daily living rather than to Lyme disease,” notes Wormser. [7]

However, these findings suggest a different conclusion: chronic Lyme disease manifestations can be severe and disabling for a subset of patients.

Clinicians and public health professionals should not dismiss the poor quality of life in Lyme disease based on studies that exclude affected individuals.

References:

Wills AB, Spaulding AB, Adjemian J et al. Long-term follow-up of patients with Lyme disease: Longitudinal analysis of clinical and quality of life measures. Clin Infect Dis, (2016).
ClinicalTrials.Gov. Evaluation, Treatment, and Follow-up of Patients With Lyme Disease at https://clinicaltrials.gov/ct2/show/NCT00028080. (Last accessed 4/20/16).
Klempner MS, Hu LT, Evans J et al. Two controlled trials of antibiotic treatment in patients with persistent symptoms and a history of Lyme disease. N Engl J Med, 345(2), 85-92 (2001).
Fallon BA, Keilp JG, Corbera KM et al. A randomized, placebo-controlled trial of repeated IV antibiotic therapy for Lyme encephalopathy. Neurology, 70(13), 992-1003 (2008).
Berende A, ter Hofstede HJ, Vos FJ et al. Randomized Trial of Longer-Term Therapy for Symptoms Attributed to Lyme Disease. N Engl J Med, 374(13), 1209-1220 (2016).
Aucott JN, Rebman AW, Crowder LA, Kortte KB. Post-treatment Lyme disease syndrome symptomatology and the impact on life functioning. Qual Life Res, 22(1), 75-84 (2013).
Wormser GP, Dattwyler RJ, Shapiro ED et al. Clinical practice guidelines for Lyme disease. Clin Infect Dis, 43(9), 1089-1134 (2006).