Rovner 2007.

Study characteristics
Methods	Study design: randomised (2‐arm parallel randomised controlled clinical trial) Sample size: 602 Method of randomisation: random‐numbers table and fixed randomisation scheme with a 1:1 allocation ratio; permuted random block design; block sizes of 4 or 6 chosen at random, to mask the blocking process Method of concealment: sealed envelopes containing treatment assignments Blinding: single‐blind Analysis: intention‐to‐treat Date the study was conducted: December 2001 ‐ July 2005
Participants	Location: USA Total N randomised: 206 Intervention n: 105 (34 % male; age M = 81, SD = 5) Control n: 101 (26 % male; age M = 81, SD = 6) Inclusion criteria: preexisting age‐related macular degeneration and neovascular age‐related macular degeneration in the other eye; age > 64 Diagnostic criteria ‐ long‐term physical condition: age‐related macular degeneration is diagnosed by ophthalmologists' dictated reports of fluorescein angiograms and ophthalmologists' confirmation of diagnosis Diagnostic criteria ‐ depression: diagnosis according to DSM‐IV criteria Exclusion criteria: diagnosis of a depressive disorder according to DSM‐IV; current treatment for depression; cognitive impairment; confounding eye conditions History of depression: Intervention: 3.4 % Control: 1.5 %
Interventions	Intervention: problem solving therapy delivered in 6 in‐home sessions (45‐60 minutes long) Control: TAU Other treatment: ‐ Duration of treatment: 2 months Length of follow‐up: 2 months (at baseline, 2, and 6 months) Other study arms: no
Outcomes	Primary outcome: incidence of depression ‐ diagnosis: DSM‐IV defined diagnosis of a depressive disorder assessed by the SADS adverse events: N/A Secondary outcome: incidence of depression ‐ cut‐off: N/A (a HDRS‐24 cut‐off score ≥ 7 was used to quantify depressive symptoms but data was not reported on) severity of depression: N/A (but comparisons of mean changes of HDRS scores were included) cost‐effectiveness: N/A cost‐utility: N/A
Notes	Language: English Funding: Grant RO1 MH61331 from the National Institute of Mental Health; grant U01 EY 015839 from the National Eye Institute; Farber Institute for Neurosciences of Thomas Jefferson University Declaration of interest: none reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"to obtain the sample, we reviewed ophthalmologists’ dictated reports of fluorescein angiograms, confirmed diagnoses with treating ophthalmologists, and contacted potential subjects...this method of ascertainment was objective and verifiable, avoided relying on ophthalmologists to identify eligible cases, and prevented other selection biases" (p. 887) "we used a random‐numbers table, sealed envelopes containing treatment assignments, and a fixed randomisation scheme with a 1:1 allocation ratio to assign subjects to 1 of the 2 study groups. We used a permuted random block design to ensure balance between treatment groups according to their time of patient enrolment. Block sizes (4 or 6) were chosen at random to mask the blocking process." (p. 887)
Allocation concealment (selection bias)	Low risk	"...sealed envelopes containing treatment assignments" (p. 887)
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	"personnel masked to treatment assignment completed central data collection, measurement, and data entry. Only the project director, statistician, and PST therapists were aware of treatment assignment. Following randomisation, the research nurses instructed all subjects on the purpose and importance of masked treatment assignment and requested that subjects not reveal any information about their study participation. We assessed rates of breaches in masking and found that unmasking occurred in 26 PST and 11 control subjects (18.0%). In all instances, subjects inadvertently revealed their treatment assignment. We compared depression rates in unmasked and masked subjects to determine whether unmasking influenced rates of diagnosing depression and found no difference (P=.80)." (p. 888)
Blinding of outcome assessment (detection bias) All outcomes	Low risk	"the outcome assessors were unaware of subjects’ treatment assignment in this single masked study." (p. 887) "personnel masked to treatment assignment completed central data collection, measurement, and data entry" (p. 888)
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	numbers randomised: problem solving therapy: n = 105; TAU: n = 101; total: N = 206 number of drop‐outs at 2 months: problem solving therapy: n = 10; TAU: n = 2; total: N = 12 number of drop‐outs at 6 months: problem solving therapy: n = 10; TAU: n = 6; total: N = 16 numbers analysed post‐intervention at 2 months: problem solving therapy: n = 95; TAU: n = 99; total: N = 194 numbers analysed follow‐up at 6 months weeks: problem solving therapy: n = 95; TAU: n = 95; total: N = 190 reasons for drop‐out (p. 887): problem solving therapy: loss of interest, too ill, death TAU: loss of interest, too ill, death Note: drop‐outs for the intervention group were reported incorrectly: the authors state that 11 subjects in the problem‐solving therapy group dropped‐out; based on other data and conducted analyses, however, only 10 subjects dropped‐out
Selective reporting (reporting bias)	Unclear risk	no protocol available
Other bias	Low risk	no